COLLABORATION AND LICENSE AGREEMENT



                              DATED JANUARY 1, 1999



                                     BETWEEN


                       AMERICAN HOME PRODUCTS CORPORATION
                               acting through its
                       WYETH-AYERST LABORATORIES DIVISION



                                       AND



                          NEUROCRINE BIOSCIENCES, INC.








                                TABLE OF CONTENTS

                                                                                                      
ARTICLE ONE - DEFINITIONS................................................................................1

    1.1    "ACQUISITION".................................................................................1
    1.2    "AFFILIATE"...................................................................................1
    1.3    "COLLABORATION PRODUCTS"......................................................................2
    1.4    "COLLABORATION TECHNOLOGY"....................................................................2
    1.5    "COMBINATION PRODUCT".........................................................................2
    1.6    "COMMERCIALLY REASONABLE EFFORTS".............................................................2
    1.7    "COMPETITION".................................................................................3
    1.8    "COMPETITIVE PRODUCTS"........................................................................3
    1.9    "COMPOUND"....................................................................................3
    1.10   "CONFIDENTIALINFORMATION".....................................................................3
    1.11   "CONTROLS" OR "CONTROLLED".....................................................................4
    1.12   "DEFAULT".....................................................................................4
    1.13   [***}.........................................................................................4
    1.14   "EFFECTIVE DATE"..............................................................................4
    1.15   "EUROPEAN UNION"..............................................................................4
    1.16   "FDA".........................................................................................4
    1.17   "FIELD OF USE"................................................................................4
    1.18   "FTE".........................................................................................4
    1.19   "FIRST COMMERCIAL SALE".......................................................................4
    1.20   "FORCE MAJEURE"...............................................................................4
    1.21   "HIT(S)"......................................................................................5
    1.22   "INTERIM CLINICAL EVALUATION POINT" OR "ICE"...................................................5
    1.23   "IND".........................................................................................5
    1.24   "JOINT CONFIDENTIAL INFORMATION"..............................................................5
    1.25   "JOINT INVENTIONS"............................................................................5
    1.26   "JOINT TECHNOLOGY"............................................................................5
    1.27   "LEAD COMPOUND(S)"............................................................................6
    1.28   "LICENSE FEES"................................................................................6
    1.29   "MAJOR EUROPEAN COUNTRY"......................................................................6
    1.30   "NDA".........................................................................................6
    1.31   "NET SALES"...................................................................................6
    1.32   "NEUROCRINE ANCILLARY TRANSPORTERS"...........................................................9
    1.33   "NEUROCRINE COMPOUND".........................................................................9
    1.34   "NEUROCRINE CONFIDENTIAL INFORMATION".........................................................9
    1.35   "NEUROCRINE INVENTION"........................................................................9
    1.36   "NEUROCRINE MATERIALS"........................................................................9
    1.37   "NEUROCRINE PROPRIETARY CHEMICAL LIBRARY".....................................................9
    1.38   "NEUROCRINE RESEARCHER".......................................................................9
    1.39   "NEUROCRINE TECHNOLOGY"......................................................................10
       (a) "Neurocrine Compound Technology".............................................................10
       (b) "Neurocrine Ancillary Transporter Technology"................................................10
       (c) "Neurocrine Transporter Technology"..........................................................10
    1.40   "NEUROCRINE TRANSPORTERS"....................................................................10
    1.41   "OHSU AGREEMENT".............................................................................10
    1.42   "PARTY"......................................................................................10
    1.43   "PATENT RIGHTS"..............................................................................11
    1.44   "PERSON".....................................................................................11
    1.45   "PIVOTAL TRIAL"..............................................................................11
    1.46   "PRIOR AGREEMENT"............................................................................11
    1.47   "PROOF OF CONCEPT"...........................................................................11
    1.48   "REGULATORY APPROVAL"........................................................................11
    1.49   "REGULATORY AUTHORITY".......................................................................11
    1.50   "REGULATORY FILINGS".........................................................................12
    1.51   "RESEARCH PLAN"..............................................................................12
    1.52   "RESEARCH PROGRAM"...........................................................................12
    1.53   "RESEARCH PROGRAMFUNDING"....................................................................12
    1.54   "RESEARCH PROGRAM MATERIALS".................................................................12
    1.55   "ROYALTIES"..................................................................................12
    1.56   "STEERING COMMITTEE".........................................................................12
    1.57   "TECHNOLOGY".................................................................................12
    1.58   "THIRD PARTY(IES)"...........................................................................12
    1.59   "THIRD PARTY ROYALTIES"......................................................................12
    1.60   "UNPATENTED PRODUCT".........................................................................12
    1.61   "VALID CLAIM"................................................................................13
    1.62   "WYETH-AYERST COMPOUND"......................................................................13
    1.63   "WYETH-AYERST CONFIDENTIAL INFORMATION"......................................................13
    1.64   "WYETH-AYERST INVENTION".....................................................................13
    1.65   "WYETH-AYERSTMATERIALS"......................................................................13
    1.66   "WYETH-AYERST PROPRIETARY CHEMICAL LIBRARY"..................................................13
    1.67   "WYETH-AYERST TECHNOLOGY"....................................................................13

ARTICLE TWO -- REPRESENTATIONS AND WARRANTIES...........................................................14

    2.1    MUTUAL REPRESENTATIONS AND WARRANTIES........................................................14
    2.2    ADDITIONAL NEUROCRINE REPRESENTATIONS, WARRANTIES AND COVENANTS..............................15
    2.3    REPRESENTATION BY LEGAL COUNSEL..............................................................17
    2.4    NEUROCRINE DISCLAIMER........................................................................17
    2.5    WYETH-AYERST DISCLAIMER......................................................................17

ARTICLE THREE -- LICENSES...............................................................................18

    3.1    LICENSE GRANT TO WYETH-AYERST................................................................18
    3.2    LICENSE GRANT TO NEUROCRINE..................................................................19
    3.3    NEUROCRINE RETAINED RIGHTS...................................................................19
    3.4    PRIOR AGREEMENT..............................................................................20
    3.5    OHSU AGREEMENT...............................................................................20

ARTICLE FOUR -- STEERING COMMITTEE......................................................................21

    4.1    CREATION; AUTHORITY..........................................................................21
    4.2    CHAIRPERSON..................................................................................21
    4.3    MEETINGS.....................................................................................21
    4.4    DECISIONS OF THE COMMITTEE...................................................................22

ARTICLE FIVE -- COLLABORATIVE RESEARCH PROGRAM AND RESEARCH FUNDING.....................................22

    5.1    RESEARCH PROGRAM.............................................................................22
    5.2    TERM.........................................................................................22
    5.3    RESEARCH PLAN................................................................................23
    5.4    CONDUCT OF THE RESEARCH PROGRAM..............................................................23
    5.5    FUNDING OF THE RESEARCH PROGRAM..............................................................23
       (a) Funding by Wyeth-Ayerst......................................................................24
       (b)    Reporting and Reconciliation..............................................................24
       (c) Records and Audits...........................................................................25
    5.6    INVENTION ASSIGNMENT AGREEMENTS..............................................................26
    5.7    REPORTING AND DISCLOSURE.....................................................................26
       (a) Reports......................................................................................26
       (b)    Quarterly Meetings........................................................................26
       (c) Disclosure...................................................................................26
    5.8    DATA.........................................................................................26
       (a) Neurocrine Data..............................................................................26
       (b) Wyeth-Ayerst Data............................................................................27
       (c) Other Research Program Data..................................................................27
       (d)    Wyeth-Ayerst Research, Clinical Development and Commercialization Data....................27
    5.9    MATERIALS....................................................................................27
       (a) Research Program Materials...................................................................27
       (b) Neurocrine Materials.........................................................................27
       (c) Wyeth-Ayerst Materials.......................................................................28

ARTICLE SIX -- SELECTION OF LEAD COMPOUNDS AND COLLABORATION PRODUCTS...................................28

    6.1    SELECTION OF LEAD COMPOUNDS DURING TERM RESEARCH PROGRAM.....................................28
    6.2    SELECTION OF LEAD COMPOUNDS AFTER TERM RESEARCH PROGRAM......................................29
    6.3    SELECTION OF COLLABORATION PRODUCTS..........................................................29
    6.4    DESIGNATION OF LEAD COMPOUNDS AND COLLABORATION PRODUCTS.....................................29

ARTICLE SEVEN - DEVELOPMENT, MANUFACTURING AND COMMERCIALIZATION........................................30

    7.1    WYETH-AYERST DEVELOPMENT.....................................................................30
    7.2    PROGRESS REPORTS.............................................................................30
    7.3    MANUFACTURING................................................................................30
    7.4    COMMERCIALIZATION OF COLLABORATION PRODUCTS..................................................30
    7.5    CO-PROMOTION.................................................................................31

ARTICLE EIGHT - LICENSE FEES............................................................................31

    8.1    LICENSE FEES.................................................................................31
    8.2    ADDITIONAL LICENSE FEES......................................................................33

ARTICLE NINE - ROYALTIES................................................................................37

    9.1    ROYALTY RATES................................................................................37
    9.2    ROYALTY ADJUSTMENTS..........................................................................39
       (a) Royalty Adjustment for Unpatented Products...................................................39
       (b) Competition..................................................................................39
    9.3    TERM OF ROYALTY..............................................................................40
    9.4    REPORTS AND PAYMENTS.........................................................................40
       (a) Cumulative Royalties.........................................................................40
       (b)    Statements and Payments...................................................................40
       (c) Taxes and Withholding........................................................................41
       (d)    Currency..................................................................................41
       (e) Maintenance of Records; Audit................................................................41
    9.5    THIRD PARTY PAYMENTS.........................................................................42
       (a) OHSU Agreement...............................................................................42
       (b) Neurocrine Technology........................................................................43
       (c) Collaboration Products.......................................................................43
       (d)  Third Party Licenses........................................................................44

ARTICLE TEN -- CONFIDENTIALITY, PUBLICATION AND PUBLIC ANNOUNCEMENTS....................................44

    10.1   CONFIDENTIALITY..............................................................................44
    10.2   AUTHORIZED DISCLOSURE........................................................................45
       (a) Each Party...................................................................................45
       (b)    Use.......................................................................................46
    10.3   SEC FILINGS..................................................................................46
    10.4   PUBLICATIONS.................................................................................46
    10.5   PUBLIC ANNOUNCEMENTS.........................................................................46
       (a) Coordination.................................................................................46
       (b) Announcements................................................................................47

ARTICLE ELEVEN - INDEMNIFICATION........................................................................47

    11.1   INDEMNIFICATION BY WYETH-AYERST..............................................................47
    11.2   INDEMNIFICATION BY NEUROCRINE................................................................47
    11.3   PROCEDURE....................................................................................48
    11.4   INSURANCE....................................................................................49

ARTICLE TWELVE - TERM AND TERMINATION...................................................................49

    12.1   GOVERNMENT APPROVALS.........................................................................49
       (a) Government Approvals.........................................................................49
       (b)    Co-operation..............................................................................49
    12.2   TERM.........................................................................................49
    12.3   EARLY TERMINATION FOR FAILURE TO DEMONSTRATE PROOF  OF CONCEPT...............................49
    12.4   TERMINATION OF COLLABORATION PRODUCT DEVELOPMENT AND COMMERCIALIZATION.......................50
    12.5   DEFAULT......................................................................................54
       (a) Wyeth-Ayerst.................................................................................54
       (b) Neurocrine...................................................................................57
    12.6   BANKRUPTCY...................................................................................58
       (a) Neurocrine...................................................................................59
       (b) Wyeth-Ayerst.................................................................................59
    12.7   ACQUISITION..................................................................................60
    12.8   LIABILITIES..................................................................................61
    12.9   DISCLAIMER...................................................................................61

ARTICLE THIRTEEN - INTELLECTUAL PROPERTY................................................................61

    13.1   INVENTIONS...................................................................................61
    13.2   PATENT PROSECUTION...........................................................................62
       (a)  Wyeth-Ayerst Inventions and Collaboration Products..........................................62
       (b) OHSU Licensed Patent Rights..................................................................62
       (c)  Neurocrine Inventions.......................................................................62
       (d)  Joint Inventions............................................................................62
    13.3   ENFORCEMENT OF PATENT RIGHTS.................................................................62
       (a) Wyeth-Ayerst Inventions......................................................................62
       (b)    Neurocrine Inventions and Joint Inventions................................................63
       (c) OHSU Licensed Patent Rights..................................................................63
       (d)    Neurocrine Technology.....................................................................64




                                    EXHIBITS

Exhibit A -- TRANSPORTERS
Exhibit B -- LEAD COMPOUND AND PROOF OF CONCEPT
Exhibit C -- PATENT RIGHTS
Exhibit D -- OHSU AGREEMENT
Exhibit E -- THIRD PARTY PATENTS
Exhibit F -- OTHER NEUROCRINE OBLIGATIONS








                       COLLABORATION AND LICENSE AGREEMENT

         THIS COLLABORATION AND LICENSE AGREEMENT (the "Agreement"), dated as of
January 1, 1999, is made by and between Neurocrine Biosciences, Inc., a Delaware
corporation with its principal place of business at 10555 Science Park Road, San
Diego,   California   92121-1102   ("Neurocrine")  and  American  Home  Products
Corporation,  acting through its Wyeth-Ayerst  Laboratories Division, a Delaware
corporation,  with a place of business at 555 East  Lancaster  Avenue St. Davids
Pennsylvania 19087 ("Wyeth-Ayerst").

     WHEREAS,   Wyeth-Ayerst  is  engaged  in  the  research,   development  and
commercialization of human pharmaceutical products;

         WHEREAS,  Neurocrine is the owner or licensee of certain  patent rights
relating to [***] which may be useful in the discovery and  development of human
pharmaceutical products;

         WHEREAS, Wyeth-Ayerst and Neurocrine have agreed to collaborate, on the
terms  and  conditions  set  forth  herein,  in the  research,  development  and
commercialization of compounds [***] (each as defined below);

         NOW,  THEREFORE,   in  consideration  of  the  mutual  representations,
warranties  and  covenants   contained   herein  and  other  good  and  valuable
consideration, the Parties agree as follows:


                                   ARTICLE ONE
                                   DEFINITIONS

         When used in this Agreement,  each of the following  capitalized  terms
shall  have the  meanings  set forth in this  Article  One.  Any  terms  defined
elsewhere in this Agreement shall be given equal weight and importance as though
set forth in this Article One.

1.1      "Acquisition"  shall mean with respect to Neurocrine,  the acquisition,
         directly or indirectly, by any Third Party of (i) securities authorized
         to cast fifty  percent  (50%) or more of the votes in any  election  of
         directors   and/or   (ii)  the  sale  or  other   transfer  of  all  or
         substantially  all of its assets.  Notwithstanding  the foregoing,  the
         sale or other transfer of substantially all of the assets of Neurocrine
         to another  direct or indirect  wholly-owned  subsidiary  of Neurocrine
         shall not constitute an Acquisition.

1.2      "Affiliate" shall mean a Person that,  directly or indirectly,  through
         one or more  intermediates,  controls,  is  controlled  by, or is under
         common  control  with the Person  specified.  For the  purposes of this
         definition, control shall mean the direct or indirect ownership of, (a)
         in the case of corporate entities,  securities  authorized to cast more
         than fifty  percent (50%) of the votes in any election for directors or
         (b) in the case of  non-corporate  entities,  more than  fifty  percent
         (50%)  ownership  interest with the power to direct the  management and
         policies of such non-corporate  entity.  Notwithstanding the foregoing,
         the term "Affiliate" shall not include subsidiaries in which a Party or
         its Affiliates  owns a majority of the ordinary voting power to elect a
         majority of the board of  directors,  but is  restricted  from electing
         such  majority  by  contract  or  otherwise,  until  such  time as such
         restrictions are no longer in effect.

1.3      "Collaboration  Products"  shall mean products  containing  one or more
         Lead Compounds as an active ingredient(s),  provided,  however, that if
         (i) none of the Compounds contained in a product are encompassed within
         the Collaboration  Technology and (ii) such product is not developed by
         Wyeth-Ayerst,  its  Affiliates or  sublicensees  for any  indication in
         which   the   [***]   and   (iii)   identification,   development   and
         commercialization  of  such  product  does  not  utilize  Collaboration
         Technology,  then such product shall not be a Collaboration Product for
         purposes of this  Agreement.  For the  purposes  of License  Fees under
         Article Eight below and Royalty  payments under Article Nine below, all
         formulations (e.g., tablets, gel caps, topical formulations, parenteral
         formulations,  sustained release formulations, etc.) of a Collaboration
         Product  will  be  considered  to be the  same  Collaboration  Product,
         regardless of the indications for which such Collaboration  Product may
         be used.

1.4      "Collaboration Technology" shall mean all Technology encompassed by the
         Neurocrine Technology, Wyeth-Ayerst Technology and Joint Technology.

1.5      "Combination  Product"  shall mean a product that  contains,  as active
         ingredients one or more Lead Compounds (or Collaboration  Products) and
         one  or  more  other   Compounds   that  are  not  Lead  Compounds  (or
         Collaboration Products).

1.6      "Commercially  Reasonable  Efforts"  shall mean  efforts and  resources
         commonly used by a Party (which efforts will be no less than those used
         by such Party in the  research  and  development  of its  products,  as
         described  below, in the one year period  preceding the Effective Date)
         for a product  owned by it or to which it has rights,  which product is
         at a similar stage in its development or product life and is of similar
         market  potential  taking into  account  efficacy,  safety,  Regulatory
         Authority  approved  labeling,   the   competitiveness  of  alternative
         products in the marketplace,  the patent and other proprietary position
         of the  product,  the  likelihood  of  Regulatory  Approval  given  the
         regulatory  structure  involved,   the  profitability  of  the  product
         including  the  royalties   payable  to  licensors  of  patent  rights,
         alternative   products  and  other   relevant   factors.   Commercially
         Reasonable Efforts shall be determined on a market-by-market  basis for
         a particular  product,  and it is anticipated  that the level of effort
         will  change  over  time,  reflecting  changes  in  the  status  of the
         Collaboration Product and the market involved.

1.7      "Competition"  shall exist during a given calendar quarter with respect
         to a  Collaboration  Product  in a  county  if,  during  such  calendar
         quarter,  one  or  more  Competitive  Products  shall  be  commercially
         available  in such  country and shall have in the  aggregate a [***] or
         greater  share of the  total  market  (based  on data  provided  by IMS
         International,  or if such data are not available,  based on such other
         data mutually agreed to by Wyeth-Ayerst and Neurocrine) in that country
         as measured by unit sales.  For purposes of this agreement,  the "total
         market" in a country shall be the sum of (x) the number of units of the
         affected  Collaboration  Product sold during such  calendar  quarter in
         such country by  Wyeth-Ayerst,  its Affiliates and sublicensees and (y)
         the number of units of Competitive Products sold in such country during
         such calendar quarter.

1.8      "Competitive  Products"  shall mean and  include  products  (other than
         Collaboration  Products  developed and  commercialized  by Wyeth-Ayerst
         pursuant to this  Agreement)  that contain  principally the same active
         chemical  entity(ies)  as a  Collaboration  Product  and  which (a) act
         through  the same  mechanism  as a  Collaboration  Product  and (b) can
         reasonably  be or are  reasonably  used  for the same  indication  as a
         Collaboration Product.  Without limitation of the foregoing,  compounds
         that  are  of  the  same  general  formulation  type  (i.e.,  oral  vs.
         parenteral vs. topical) as a  Collaboration  Product would generally be
         considered  Competitive Products while compounds of a different general
         formulation  type from a  Collaboration  Product would generally not be
         considered  Competitive  Products unless the compound and Collaboration
         Product  are  reasonably  used  (other  than de minimis  usage) for the
         treatment of the same indication.

1.9      "Compound"  shall mean a chemical  compound or substance  together with
         all complexes, mixtures and other combinations,  prodrugs, metabolites,
         enantiomers, salt forms, racemates, and isomers thereof.

1.10     "Confidential  Information"  shall  mean with  respect  to each  Party,
         non-public  proprietary data or information which belong in whole or in
         part  to such  Party  and/or  information  designated  as  Confidential
         Information of such Party hereunder.

1.11     "Controls" or "Controlled"  shall mean with respect to Technology,  the
         possession  of the  ability to grant  licenses or  sublicenses  without
         violating the terms of any agreement or other  arrangement with, or the
         rights of, any Third Party.

1.12     "Default"   shall   mean  with   respect   to  a  Party  that  (i)  any
         representation  or warranty of such Party set forth  herein  shall have
         been untrue in any material  respect when made or (ii) such Party shall
         have  failed  to  perform  any  material  obligation  set forth in this
         Agreement.

1.13     [***] shall be as defined in Exhibit A.

1.14     "Effective Date" shall mean January 1, 1999.

1.15     "European  Union" shall mean, from time to time,  those countries that
         are members of the European Union.

1.16     "FDA" shall mean the Federal Food and Drug Administration of the United
         States  Department of Health and Human Services or any successor agency
         thereof.

1.17     "Field of Use" shall mean all therapeutic, prophylactic and diagnostic
         uses.

1.18     "FTE" shall mean full time equivalent scientific person year consisting
         of a  minimum  of a  total  [***]  per  year of  scientific  work on or
         directly related to the Research  Program.  Work on or directly related
         to  the  Research   Program  can  include,   but  is  not  limited  to,
         experimental   laboratory  work,  recording  and  writing  up  results,
         reviewing  literature and references,  holding scientific  discussions,
         managing and leading  scientific staff,  carrying out management duties
         related  to  the  Research  Program,  and to  the  extent  specifically
         approved  by  Wyeth-Ayerst,  writing up  results  for  publications  or
         presentation  and  attending  or  presenting  appropriate  seminars and
         symposia.

1.19     "First  Commercial  Sale" shall mean with respect to any  Collaboration
         Product   approved  for   commercial   sale,   the  first  transfer  by
         Wyeth-Ayerst,   its   Affiliates   and/or  its   sublicensees   of  the
         Collaboration  Product to a  non-Affiliate  Third Party in exchange for
         cash or some equivalent to which value can be assigned.

1.20     "Force Majeure" shall mean any occurrence beyond the reasonable control
         of  a  Party  that  prevents  or  substantially   interferes  with  the
         performance by the Party of any of its obligations  hereunder,  if such
         occurs by reason of any act of God, flood, fire, explosion, earthquake,
         strike,   lockout,  labor  dispute,   casualty  or  accident;  or  war,
         revolution,  civil  commotion,  acts of  public  enemies,  blockage  or
         embargo;  or any  injunction,  law,  order,  proclamation,  regulation,
         ordinance,   demand  or   requirement  of  any  government  or  of  any
         subdivision,  authority or  representative  of any such government;  or
         breakdown  of plant,  inability  to  procure or use  materials,  labor,
         equipment,  transportation,  or energy sufficient to meet manufacturing
         needs  without  the  necessity  of  allocation;   or  any  other  cause
         whatsoever,  whether  similar or dissimilar to those above  enumerated,
         beyond the reasonable  control of such Party,  if and only if the Party
         affected shall have used  reasonable  efforts to avoid such  occurrence
         and to remedy it promptly if it shall have occurred.

1.21     "Hit(s)" shall mean Compounds  derived from the Neurocrine  Proprietary
         Chemical Library, the Wyeth-Ayerst  Proprietary Chemical Library or any
         other  library  selected  by the  Parties,  which are  screened  in the
         conduct of the Research  Program and test positive in screening  assays
         [***]. For the purposes of this definition, the Steering Committee will
         determine  what shall  constitute  a positive  test with respect to any
         screening   assays  selected  for  the  Research   Program  and  it  is
         anticipated  that,  depending on results  obtained in the course of the
         Research Program, what constitutes a positive test may change from time
         to time.

1.22     "Interim  Clinical  Evaluation Point" or "ICE" shall mean, with respect
         to any  Collaboration  Product,  the development  milestone  indicating
         [***], as decided by Wyeth-Ayerst's  Development  Operating  Committee.
         [***]. In addition, [***].  Notwithstanding the foregoing, in the event
         Wyeth-Ayerst shall make the decision [***], ICE shall be deemed to have
         been met.

1.23     "IND" shall mean an  Investigational  New Drug  Application  covering a
         Collaboration  Product  filed with the FDA pursuant to 21 CFR 312.20 or
         an equivalent  foreign  filing  required for the clinical  testing of a
         pharmaceutical product.

1.24     "Joint  Confidential  Information" shall mean Confidential  Information
         owned jointly by Wyeth-Ayerst and Neurocrine or otherwise designated as
         Joint Confidential Information hereunder.

1.25     "Joint Inventions" shall be as defined in Section 13.1 hereof.

1.26     "Joint  Technology"  shall  mean  Technology,  which is  discovered  or
         invented  jointly by Neurocrine  personnel and  Wyeth-Ayerst  personnel
         during the term of this Agreement.

1.27     "Lead Compound(s)" shall mean those Compounds (i) [***], (ii) that meet
         the  criteria set forth on Exhibit B hereto and (iii) that are selected
         by the Steering  Committee or  Wyeth-Ayerst  in accordance with Article
         Six, provided,  however, that Lead Compounds shall specifically exclude
         any Compounds  [***].  Notwithstanding  the foregoing,  for purposes of
         calculating Net Sales and determining License Fees and Royalty payments
         under this  Agreement,  a Lead Compound  together  with all  complexes,
         mixtures and other combinations,  prodrugs,  metabolites,  enantiomers,
         salt forms,  racemates,  isomers,  and  derivatives  thereof,  shall be
         considered to be a single Lead Compound.

1.28     "License Fees" shall mean the payments to be made by  Wyeth-Ayerst  to
         Neurocrine upon occurrence of certain events as set forth in Article
         Eight.

1.29     "Major  European  Country"  shall mean France,  Germany,  Italy or the
         United Kingdom.

1.30     "NDA"  shall  mean  a  New  Drug  Application  (or  Biologics   License
         Application, if applicable) covering a Collaboration Product filed with
         the FDA pursuant to 21 CFR 314 or an equivalent foreign filing required
         for marketing approval of a pharmaceutical product.

1.31     "Net Sales" shall mean,  with respect to a Collaboration  Product,  all
         proceeds  actually  received  from the sale or other  disposition  of a
         Collaboration  Product by Wyeth-Ayerst,  its Affiliates or sublicensees
         to  unrelated   Third  Parties,   less  the  reasonable  and  customary
         deductions  from such gross amounts  actually paid by or charged to the
         account of Wyeth-Ayerst, including, without limitation,


                  (a)      trade, cash and quantity  discounts actually allowed 
                           and taken directly with respect to such sales;

                  (b)      amounts  repaid,   credits  or  allowances   actually
                           granted for damaged goods, defects,  recalls, returns
                           or   rejections   of   Collaboration    Product   and
                           retroactive price reductions;

                  (c)      sales or similar taxes actually paid by or charged to
                           the  account  of  Wyeth-Ayerst,   its  Affiliates  or
                           sublicensees   without  offset  (including,   without
                           limitation,  duties  or  other  governmental  charges
                           levied on, absorbed or otherwise  imposed on the sale
                           of Collaboration  Product, value added taxes or other
                           governmental   charges  otherwise   measured  by  the
                           billing  amount,  when  included in billing,  but not
                           including  national,  state or local  taxes  based on
                           income);

                  (d)      charge  back  payments  and  rebates  granted  to (i)
                           managed  health  care  organizations,  (ii)  federal,
                           state and/or  local  governments  or their  agencies,
                           (iii)  purchasers  and  reimbursers,  or  (iv)  trade
                           customers, including, without limitation, wholesalers
                           and chain and pharmacy buying groups; and

                  (e)      freight,  postage,   shipping,   customs  duties  and
                           insurance  charges  to  the  extent  included  in the
                           proceeds actually received from the customer.

         For the purposes of  determining  Net Sales  hereunder,  a  sublicensee
         shall  include  a  Third  Party  who,  pursuant  to an  agreement  with
         Wyeth-Ayerst,  distributes Collaboration Products, provided, such Third
         Party also, as required by such agreement,  conducts  promotion  and/or
         marketing  activities in the applicable  territory.  Net Sales shall be
         determined  in  accordance  with  United  States   generally   accepted
         accounting principles consistently applied. A "sale" shall also include
         the  transfer  or other  disposition  of a  Collaboration  Product  for
         consideration other than cash, in which case such consideration will be
         valued  at  the  fair  market  value  thereof.  In  the  event  that  a
         Collaboration  Product is sold either for consideration other than cash
         or as part of a bundled  product,  the Net Sales of such  Collaboration
         Product  will be  calculated  based on the  average  unit price of such
         Collaboration  Product  when sold  (other  than as part of a bundle) in
         cash   transactions   in  such  country.   In  the  event  that,  on  a
         country-by-country  basis, a Collaboration  Product is sold in the form
         of a Combination  Product,  the Net Sales for such Combination  Product
         will be calculated as follows:

                   (i)      If Wyeth-Ayerst,  its Affiliates and/or sublicensees
                            separately sells, in such country, (x) Collaboration
                            Products    containing    as   their   sole   active
                            ingredient(s)  the  same  Lead  Compound(s)  as  are
                            contained in such Combination  Product and (y) other
                            products    containing    as   their   sole   active
                            ingredient(s)   the  other   active   component   or
                            components  in  such  Combination  Product,  the Net
                            Sales attributable to such Combination Product shall
                            be calculated by multiplying actual Net Sales of the
                            Combination    Product   by   the    [***],    which
                            Collaboration  Product contains,  as the sole active
                            ingredient(s),  the same Lead  Compound(s) as are in
                            such Combination Product and [***], which product(s)
                            contain,  as their  sole  active  ingredient(s)  any
                            other  active   component  or   components   in  the
                            Combination Product.

                   (ii)     If Wyeth-Ayerst,  its Affiliates and/or sublicensees
                            separately  sells,  in such  country,  Collaboration
                            Products    containing    as   their   sole   active
                            ingredient(s)  the  same  Lead  Compound(s)  as  are
                            contained  in such  Combination  Product  but do not
                            separately  sell,  in such country,  other  products
                            containing  as their sole active  ingredient(s)  the
                            other  active   component  or   components  in  such
                            Combination  Product,  the Net Sales attributable to
                            such  Combination  Product  shall be  calculated  by
                            multiplying  the  Net  Sales  of  such   Combination
                            Product by the [***],  which  Collaboration  Product
                            contains, as the sole active ingredient(s), the same
                            Lead Compound(s) as are in such Combination Product,
                            [***].
                  (iii)    If Wyeth-Ayerst,  its Affiliates and/or  sublicensees
                           do   not   separately    sell,   in   such   country,
                           Collaboration   Products  containing  as  their  sole
                           active ingredient(s) the same Lead Compound(s) as are
                           contained in such Combination  Product, the Net Sales
                           attributable  to such  Combination  Product  shall be
                           calculated  by  multiplying  the  Net  Sales  of such
                           Combination Product by the [***].

         Notwithstanding  the  foregoing,   Net  Sales  shall  not  include  any
         consideration received by Wyeth-Ayerst,  its Affiliates or sublicensees
         in respect of the sale,  use or other  disposition  of a  Collaboration
         Product in a country as part of a clinical  trial  prior to the receipt
         of all Regulatory  Approvals required to commence full commercial sales
         of such Collaboration Product in such country.

1.32     "Neurocrine Ancillary  Transporters" shall mean [***] as defined on 
         Exhibit A.

1.33     "Neurocrine Compound" shall mean any Compound,  which is (a) within the
         Neurocrine  Proprietary Chemical Library, and (b) is screened under the
         Research  Program  for  activity  against the  Neurocrine  Transporters
         together with all complexes, mixtures and other combinations, prodrugs,
         metabolites, enantiomers, salt forms, racemates, and isomers thereof.

1.34     "Neurocrine   Confidential   Information"   shall   mean   Confidential
         Information  owned by Neurocrine or otherwise  designated as Neurocrine
         Confidential   Information   hereunder  but  shall  not  include  Joint
         Confidential Information.

1.35     "Neurocrine Invention" shall have the meaning set forth in Section 13.1
         hereof.

1.36     "Neurocrine  Materials"  shall  mean  Neurocrine  proprietary  research
         materials  including,  but not limited to,  Neurocrine  Compounds,  the
         Neurocrine Proprietary Chemical Library,  assays, physical databases of
         chemical structures of Compounds in the Neurocrine Proprietary Chemical
         Library, reagents and materials derived therefrom. Neurocrine Materials
         will  not  include  Research  Program  Materials.  Neurocrine  will own
         Neurocrine Materials supplied by Neurocrine to Wyeth-Ayerst hereunder.

1.37     "Neurocrine  Proprietary  Chemical  Library" shall mean those Compounds
         that  Neurocrine,  as of the Effective  Date owns or Controls,  or that
         come into Neurocrine's Control during the term of the Research Program.

1.38     "Neurocrine   Researcher"  shall  mean  professional   researchers  and
         scientists  employed  by  Neurocrine  and  having at least a  Bachelors
         Degree in science and other academic  and/or  professional  credentials
         demonstrating  reasonably  appropriate  expertise  for  the  task to be
         performed by such  Neurocrine  Researcher  in carrying out the Research
         Plan.

1.39     "Neurocrine  Technology" shall mean the Neurocrine Compound Technology,
         Neurocrine   Ancillary   Transporter   Technology  and  the  Neurocrine
         Transporter Technology, each as defined below.

                  (a)      "Neurocrine   Compound  Technology"  shall  mean  all
                           Technology  (other  than Joint  Technology)  owned or
                           Controlled by Neurocrine on the Effective Date and/or
                           during the term of this  Agreement,  which (i) claims
                           or  describes  Lead  Compounds  and/or  Collaboration
                           Products  and/or  (ii) is  developed,  discovered  or
                           invented by Neurocrine in the conduct of the Research
                           Program  and/or  (iii)  is  necessary  or  useful  to
                           develop,  make,  use or sell  Lead  Compounds  and/or
                           Collaboration Products.

                  (b)      "Neurocrine Ancillary  Transporter  Technology" shall
                           mean all  Technology  (other  than Joint  Technology)
                           owned or  Controlled  by  Neurocrine on the Effective
                           Date or during the term of the Research  Program that
                           claims,  describes  or  relates  to  the  use  of the
                           Neurocrine Ancillary Transporters.

                  (c)      "Neurocrine  Transporter  Technology"  shall mean all
                           Technology  (other  than Joint  Technology)  owned or
                           Controlled by  Neurocrine  on the  Effective  Date or
                           during the term of the Research  Program that claims,
                           describes  or  relates  to the use of the  Neurocrine
                           Transporters.  Neurocrine Transporter Technology will
                           specifically include, without limitation,  the Patent
                           Rights set forth on Exhibit C hereto.

1.40 "Neurocrine Transporters" shall mean [***] as defined on Exhibit A.

1.41     "OHSU Agreement" shall mean the Amended and Restated License  Agreement
         dated January 1, 1999 by and between Oregon Health Sciences  University
         ("OHSU") and  Neurocrine (a complete copy of which has been provided to
         and  approved  by  Wyeth-Ayerst  prior to the date this  Agreement  was
         signed by the Parties  and which is  attached  hereto as Exhibit D), as
         such agreement may be amended from time to time (subject to the consent
         of  Wyeth-Ayerst  to the  extent  required  under the  Agreement  dated
         January 1, 1999 by and among OHSU, Wyeth-Ayerst and Neurocrine.)

1.42     "Party" shall mean Wyeth-Ayerst or Neurocrine, as the case may be, and 
         "Parties" shall mean Wyeth-Ayerst and Neurocrine.

1.43     "Patent  Rights"  shall  mean the rights  and  interests  in and to all
         issued  patents  and  pending  patent   applications  in  any  country,
         including,    without   limitation,   all   provisional   applications,
         substitutions,  continuations,  continuations-in-part,  divisions,  and
         renewals,    all   letters    patent   granted    thereon,    and   all
         patents-of-addition,   reissues,   reexaminations   and  extensions  or
         restorations by existing or future extension or restoration mechanisms,
         including,  without limitation Supplementary Protection Certificates or
         the equivalent thereof.

1.44     "Person" shall mean any  individual,  firm,  corporation,  partnership,
         limited liability company, trust,  unincorporated organization or other
         entity or a government  agency or political  subdivision  thereto,  and
         shall include any successor (by merger or otherwise) of such Person.

1.45     "Pivotal  Trial" shall mean clinical  trial which,  if the  pre-defined
         endpoints  are  met,  is  intended  to  be  submitted  as  part  of  an
         application for marketing approval as statistically significant data in
         support  of  the  product's   safety  and  efficacy  for  the  intended
         indication.

1.46     "Prior Agreement" shall mean the agreement dated August 15, 1996 by and
         between Northwest NeuroLogic, Inc. and Wyeth-Ayerst, as amended.

1.47     "Proof of Concept" shall mean, with respect to either of the Neurocrine
         Transporters,  the successful achievement of both the in vitro Proof of
         Concept and the in vivo Proof of Concept  criteria for such  Neurocrine
         Transporter, as set forth in Exhibit B.

1.48     "Regulatory Approval" shall mean the technical,  medical and scientific
         licenses,  registrations,   authorizations  and  approvals  (including,
         without limitation, approvals of NDAs, supplements and amendments, pre-
         and post- approvals,  pricing and third party reimbursement  approvals,
         and labeling  approvals)  of any  national,  supra-national,  regional,
         state or  local  regulatory  agency,  department,  bureau,  commission,
         council or other  governmental  entity,  necessary for the development,
         manufacture,  distribution,  marketing, promotion, offer for sale, use,
         import, export or sale of Lead Compounds or Collaboration Product(s) in
         a regulatory jurisdiction.

1.49     "Regulatory  Authority"  shall  mean  any  national  (e.g.,  the  FDA),
         supra-national  (e.g.,  the  European  Commission,  the  Council of the
         European  Union, or the European Agency for the Evaluation of Medicinal
         Products),  regional,  state or local  regulatory  agency,  department,
         bureau,  commission,  council  or  other  governmental  entity  in each
         country  of the  Territory  involved  in  the  granting  of  Regulatory
         Approval for a Lead Compound or a Collaboration Product.

1.50     "Regulatory Filings" shall mean, collectively,  INDs, Biologics License
         Applications,  Drug  Master  Files,  NDAs  and/or any other  comparable
         filings  as  may  be  required  by  Regulatory  Authorities  to  obtain
         Regulatory Approvals.

1.51     "Research Plan" will be as defined in Section 5.3 below.

1.52     "Research  Program"  shall  mean  the  collaborative  research  program
         conducted  by  Neurocrine  and  Wyeth-Ayerst  and funded,  in part,  by
         Wyeth-Ayerst in accordance with the provisions of Article Five below.

1.53     "Research Program Funding" will be as defined in Section 5.5 below.

1.54     "Research Program Materials" shall mean and include clones, cell lines,
         Compounds,  assays,  databases,  electronic  and physical  databases of
         chemical  structures  which,  in each case, are developed by Neurocrine
         and/or  Wyeth-Ayerst  during  the  course of  conduct  of the  Research
         Program.  Research  Program  Materials also will include the Neurocrine
         Transporters and Neurocrine  Ancillary  Transporters  and clones,  cell
         lines and other materials encompassing,  expressing,  and/or containing
         the Neurocrine Transporters and/or Neurocrine Ancillary Transporters.

1.55     "Royalties"  shall mean those  royalties  payable  by  Wyeth-Ayerst  to
         Neurocrine pursuant to Article Nine of this Agreement.

1.56     "Steering  Committee"  shall have the  meaning set forth in Section 4.1
         hereof.

1.57     "Technology"   shall  mean  proprietary   data,   information  and  all
         intellectual  property,  including  but not limited to, trade  secrets,
         know-how,  inventions and  technology,  whether  patentable or not, and
         Patent  Rights  directed to products,  processes,  formulations  and/or
         methods.
1.58  "Third   Party(ies)"   shall  mean  any  Person  other  than   Neurocrine,
Wyeth-Ayerst and their respective Affiliates.

1.59     "Third Party  Royalties"  shall mean  royalties  payable by Neurocrine,
         Wyeth-Ayerst,  its Affiliates or sublicensees to a non-Affiliate  Third
         Party (or multiple  non-Affiliate  Third  Parties) to make,  have made,
         use, sell,  offer for sale or import  Collaboration  Products where the
         royalty  payable to such  non-Affiliate  Third Party is based on Patent
         Rights owned or Controlled by such Third Party.

1.60     "Unpatented  Product"  shall mean a  Collaboration  Product the making,
         using or sale of which is not  claimed  or  described  in at least  one
         Valid Claim included in the Collaboration Technology.

1.61     "Valid Claim" shall mean a claim of an issued and unexpired patent or a
         claim of a pending patent  application  which has not been held invalid
         or  unenforceable  by a court or other  government  agency of competent
         jurisdiction  from which no appeal can be or has been taken and has not
         been admitted to be invalid or unenforceable through  re-examination or
         disclaimer  or  otherwise,  provided,  however,  that if a  claim  of a
         pending patent application shall not have issued within [***] after the
         filing date from which such claim takes  priority  such claim shall not
         constitute a Valid Claim for the purposes of this Agreement.

1.62     "Wyeth-Ayerst Compound" shall mean any Compound (a) which is within the
         Wyeth-Ayerst  Proprietary  Chemical  Library  and (b) which is screened
         under the Research Program or by Wyeth-Ayerst  under this Agreement for
         activity against a Neurocrine  Transporter together with all complexes,
         mixtures and other combinations,  prodrugs,  metabolites,  enantiomers,
         salt forms, racemates, and isomers thereof.

1.63     "Wyeth-Ayerst   Confidential   Information"   shall  mean  Confidential
         Information   owned  by   Wyeth-Ayerst   or  otherwise   designated  as
         Wyeth-Ayerst  Confidential  Information hereunder but shall not include
         Joint Confidential Information.

1.64     "Wyeth-Ayerst  Invention"  shall have the  meaning set forth in Section
         13.1 hereof.

1.65     "Wyeth-Ayerst  Materials" shall mean Wyeth-Ayerst  proprietary research
         materials including,  but not limited to, Wyeth-Ayerst  Compounds,  the
         Wyeth-Ayerst  Proprietary Chemical Library,  assays, physical databases
         of chemical  structures  of Compounds in the  Wyeth-Ayerst  Proprietary
         Chemical   Library,   reagents   and   materials   derived   therefrom.
         Wyeth-Ayerst  Materials will not include  Research  Program  Materials.
         Wyeth-Ayerst  will own  Wyeth-Ayerst  Materials  provided to Neurocrine
         hereunder.

1.66    "Wyeth-Ayerst  Proprietary  Chemical Library" shall mean those Compounds
        that Wyeth-Ayerst,  as of the Effective Date, owns or Controls,  or that
        come into Wyeth-Ayerst's Control during the term of this Agreement,  and
        any  other   Compounds  not  Controlled  by   Wyeth-Ayerst,   but  which
        Wyeth-Ayerst  has the right to  develop  and  commercialize,  including,
        without  limitation,  the right to screen such  Compounds  for  activity
        against the Neurocrine  Transporters  without violating the terms of any
        agreement between Wyeth-Ayerst and a Third Party.

1.67    "Wyeth-Ayerst  Technology"  shall mean all Technology  (other than Joint
        Technology)  owned or Controlled by  Wyeth-Ayerst  on the Effective Date
        and/or during the term of this Agreement (a) which relates  specifically
        to, claims or describes Lead  Compounds  and/or  Collaboration  Products
        and/or (b) is developed,  discovered or invented by  Wyeth-Ayerst in the
        conduct  of the  Research  Program,  (c)  is  developed,  discovered  or
        invented by Wyeth-Ayerst  personnel  directly  resulting from the use of
        Neurocrine  Technology  or Joint  Technology  and/or (d) is necessary or
        useful  to  make,  use  or  sell  Lead  Compounds  and/or  Collaboration
        Products.


                                   ARTICLE TWO
                         REPRESENTATIONS AND WARRANTIES

2.1      Mutual  Representations  and Warranties.  Each Party hereby represents,
         warrants and covenants to the other Party that:

         (a)      the execution,  delivery to the other Party and performance by
                  it of this  Agreement  and its  compliance  with the terms and
                  provisions of this  Agreement  does not and will not conflict,
                  in any material respect,  with or result in a breach of any of
                  the  terms  or  provisions   of  (x)  any  other   contractual
                  obligations of such Party,  (y) the provisions of its charter,
                  operating  documents  or  bylaws,  or  (z)  any  order,  writ,
                  injunction  or decree of any court or  governmental  authority
                  entered  against it or by which it or any of its  property  is
                  bound  except   where  such  breach  or  conflict   would  not
                  materially  impact the Party's ability to meet its obligations
                  hereunder,  and (ii) it has not granted to any Third Party any
                  right which would  conflict in any  material  respect with the
                  rights granted by it to the other Party hereunder;

         (b)      this  Agreement is a legal and valid  obligation  binding upon
                  such Party and enforceable in accordance with its terms except
                  as  (i)   enforceability   may  be  limited   by   bankruptcy,
                  insolvency,   reorganization,   moratorium   or  similar  laws
                  affecting  the  enforcement  of  creditors'  rights  and  (ii)
                  equitable principles of general applicability;

         (c)      such Party is a corporation  duly organized,  validly existing
                  and in good  standing  under  the  laws of the  state or other
                  jurisdiction  of  incorporation  or  formation  and  has  full
                  corporate power and authority to enter into this Agreement and
                  to carry out the provisions  hereof except where failure to be
                  in good  standing  would not  materially  impact  the  Party's
                  ability to meet its obligations hereunder;

         (d)      such  Party is duly  authorized,  by all  requisite  corporate
                  action,   to  execute  and  deliver  this  Agreement  and  the
                  execution,  delivery and performance of this Agreement by such
                  Party does not require any shareholder action or approval, and
                  the Person executing this Agreement on behalf of such Party is
                  duly authorized to so by all requisite corporate action; and

         (e)      no  consent,   approval,   order  or   authorization   of,  or
                  registration,   qualification,   designation,  declaration  or
                  filing  with,  any  federal,   state  or  local   governmental
                  authority is required on the part of such Party in  connection
                  with the valid  execution,  delivery and  performance  of this
                  Agreement,   except  for  any  filings  under  any  applicable
                  securities  laws and except where the failure to obtain any of
                  the foregoing would not have a material  adverse impact on the
                  ability of such Party to meets its obligations hereunder.

2.2      Additional  Neurocrine   Representations,   Warranties  and  Covenants.
         Neurocrine represents, warrants and covenants to Wyeth-Ayerst that:

         (a)      it has the full right, power and authority to grant the 
                  licenses granted to Wyeth-Ayerst under Article Three hereof;

         (b)      all Patent Rights included  within the Neurocrine  Transporter
                  Technology   and/or  the  Neurocrine   Ancillary   Transporter
                  Technology  which are  existing as of the  Effective  Date are
                  listed on Exhibit C attached  hereto and, as of the  Effective
                  Date,  the  Patent  Rights   included  within  the  Neurocrine
                  Technology are existing and, to its knowledge, are not invalid
                  or unenforceable, in whole or in part;

         (c)      except as disclosed to  Wyeth-Ayerst in writing and except for
                  the nonexclusive  licenses  granted to Neurocrine  pursuant to
                  Article  Three  of the OHSU  Agreement  or  retained  by OHSU,
                  Howard  Hughes   Medical   Institute  and  the  United  States
                  Government  pursuant  to  Article  Five  of the  OHSU  License
                  Agreement,  to its  knowledge (i) it is the sole and exclusive
                  owner or the exclusive licensee of the Neurocrine  Technology,
                  including,  without  limitation,  all Patent  Rights  included
                  therein,  and (ii) no Person  (except OHSU,  the Howard Hughes
                  Medical  Institute  and  the  United  States  Government  with
                  respect to those Patent Rights  licensed to  Neurocrine  under
                  the OHSU Agreement), has any right, title or interest in or to
                  the Neurocrine Technology;

         (d)      except  as  disclosed  to  Wyeth-Ayerst  in  writing,  to  its
                  knowledge (i) all inventors (who are known as of the date this
                  Agreement is signed by each of the Parties) of any  inventions
                  included within the Neurocrine  Technology have assigned their
                  entire right, title and interest in and to such inventions and
                  the corresponding  Patent Rights to Neurocrine or, in the case
                  of  inventions  and Patent  Rights  licensed by Oregon  Health
                  Sciences  University to Neurocrine,  to Oregon Health Sciences
                  University, and (ii) no Person, other than those Persons named
                  as  inventors  on any  patent or patent  application  included
                  within  the  Neurocrine  Technology,  is an  inventor  of  the
                  invention(s) claimed in such patent or patent application;

         (e)      except  as   disclosed   to   Wyeth-Ayerst   in  writing,   to
                  Neurocrine's knowledge,  OHSU has (i) complied with all of its
                  obligations under applicable United States Government laws and
                  regulations with respect to any inventions included within the
                  Neurocrine  Technology which inventions are subject inventions
                  of a funding  agreement  between  OHSU and the  United  States
                  Government  or any agency  thereof and (ii)  elected to retain
                  title to any such invention as provided in 37 CFR Part 401;

         (f)      as of the  date  this  Agreement  is  signed  by  each  of the
                  Parties, there are no claims, judgments or settlements against
                  or  owed  by  Neurocrine  or,  to its  knowledge,  pending  or
                  threatened  claims or  litigation  relating to the  Neurocrine
                  Technology  and during the term of this  Agreement  Neurocrine
                  shall promptly notify  Wyeth-Ayerst in writing,  upon learning
                  of  any  such  actual  or   threatened   claim,   judgment  or
                  settlement;

         (g)      during  the  term  of  this  Agreement   Neurocrine  will  use
                  Commercially  Reasonable  Efforts not to  diminish  the rights
                  under  the  Neurocrine  Technology  provided,   however,  that
                  termination of the OHSU Agreement (i) by reason of the failure
                  by  Wyeth-Ayerst,   as  a  sublicensee  thereunder,   to  meet
                  obligations  set forth in Articles Nine and Ten thereof or any
                  other  obligations  of a  sublicensee  thereunder  or  (ii) by
                  reason of any default by Wyeth-Ayerst hereunder, shall not, in
                  either instance, constitute a breach of this subparagraph (g);

         (h)      except  as  set  forth  on  Exhibit  E,  as of the  date  this
                  Agreement is signed by each of the Parties, it is not aware of
                  any patent,  patent application or other intellectual property
                  right of any Third  Party  which  could  materially  adversely
                  affect the ability of either Party to carry out its respective
                  obligations  hereunder  or  the  ability  of  Wyeth-Ayerst  to
                  exercise or exploit  any of the rights or licenses  granted to
                  it under this Agreement;

         (i)      except  as set forth on  Exhibit  F hereof,  the terms of this
                  Agreement  do not  conflict in any  material  respect with the
                  terms of any other Neurocrine obligations; and

         (j)      it has no knowledge of any  material  information,  other than
                  information  provided to  Wyeth-Ayerst in writing prior to the
                  signing of this Agreement,  which would negatively  affect the
                  ability of Wyeth-Ayerst to use the Neurocrine  Transporters or
                  the Neurocrine Ancillary Transporters.

2.3      Representation  by Legal Counsel.  Each Party hereto represents that it
         has been represented by legal counsel in connection with this Agreement
         and acknowledges  that it has  participated in the drafting hereof.  In
         interpreting  and applying the terms and provisions of this  Agreement,
         the Parties agree that no presumption shall exist or be implied against
         the Party which drafted such terms and provisions.

2.4      Neurocrine Disclaimer. EXCEPT AS EXPRESSLY PROVIDED IN SECTIONS 2.1 AND
         2.2  HEREOF,  NEUROCRINE  MAKES NO OTHER  REPRESENTATION  OR  WARRANTY,
         EITHER  EXPRESS  OR  IMPLIED,   INCLUDING,   WITHOUT  LIMITATION,   ANY
         WARRANTIES OF  MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE WITH
         RESPECT TO ANY NEUROCRINE MATERIALS,  INCLUDING WITHOUT LIMITATION, THE
         NEUROCRINE   TRANSPORTERS   AND  NEUROCRINE   ANCILLARY   TRANSPORTERS.
         ADDITIONALLY,  NEUROCRINE MAKES NO REPRESENTATION  OR WARRANTY,  EITHER
         EXPRESS  OR  IMPLIED,  THAT  THE  MANUFACTURE,  USE OR SALE OF ANY LEAD
         COMPOUND OR  COLLABORATION  PRODUCT WILL NOT INFRINGE THE  INTELLECTUAL
         PROPERTY RIGHTS OF ANY THIRD PARTY.

2.5      Wyeth-Ayerst  Disclaimer.  EXCEPT AS EXPRESSLY  PROVIDED IN SECTION 2.1
         HEREOF,  WYETH-AYERST MAKES NO OTHER REPRESENTATION OR WARRANTY, EITHER
         EXPRESS OR IMPLIED,  INCLUDING,  WITHOUT LIMITATION,  ANY WARRANTIES OF
         MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE WITH RESPECT TO ANY
         WYETH-AYERST MATERIALS, ANY LEAD COMPOUND OR ANY COLLABORATION PRODUCT.
         ADDITIONALLY,  WYETH-AYERST MAKES NO REPRESENTATION OR WARRANTY, EITHER
         EXPRESS OR IMPLIED THAT THE DISCOVERY, DEVELOPMENT, MANUFACTURE, USE OR
         SALE OF ANY LEAD  COMPOUND OR  COLLABORATION  PRODUCT WILL NOT INFRINGE
         THE INTELLECTUAL PROPERTY RIGHTS OF ANY THIRD PARTY.


                                  ARTICLE THREE
                                    LICENSES

3.1      License Grant to Wyeth-Ayerst.  Except as set forth in Section 3.3 
         below, Neurocrine hereby grants to Wyeth-Ayerst:

         (a)      the sole and exclusive  worldwide  right and license,  with no
                  right to sublicense  (except (i) to Wyeth-Ayerst's  Affiliates
                  and  (ii)  to  any  sublicensee  of  a  Lead  Compound  and/or
                  Collaboration  Product in so far as  reasonably  necessary for
                  such   sublicensee  to  develop  such  Lead  Compound   and/or
                  Collaboration  Product),  under both the Neurocrine Technology
                  and Neurocrine's interest in any Joint Technology,  to use the
                  Neurocrine   Transporters   for  the   identification   and/or
                  development  of Lead Compounds and  Collaboration  Products in
                  the Field of Use;

         (b)      the sole and exclusive  worldwide right and license,  with the
                  right to sublicense to Affiliates of  Wyeth-Ayerst  and/or one
                  or more Third Parties,  under both the  Neurocrine  Technology
                  and Neurocrine's  interest in any Joint  Technology,  to make,
                  have made, use, import,  market,  offer for sale and sell Lead
                  Compounds and Collaboration Products in the Field of Use;

         (c)      during  the  term  of  the  Research  Program,  the  sole  and
                  exclusive  right  and  license,  with no right  to  sublicense
                  (except  to   Wyeth-Ayerst's   Affiliates),   under  both  the
                  Neurocrine Ancillary  Transporter  Technology and Neurocrine's
                  interest  in  any  Joint  Technology,  to use  the  Neurocrine
                  Ancillary  Transporters  for the [***] of Lead  Compounds  and
                  Collaboration Products;

         (d)      after the term of the Research Program, a non-exclusive  right
                  and  license,   with  no  right  to   sublicense   (except  to
                  Wyeth-Ayerst's  Affiliates),  under the  Neurocrine  Ancillary
                  Transporter   Technology  to  use  the  Neurocrine   Ancillary
                  Transporters for the [***] of Lead Compounds and Collaboration
                  Products;

         (e)      during the term of this  Agreement,  a nonexclusive  right and
                  license,   with  no  right  to   sublicense   (except  (i)  to
                  Wyeth-Ayerst  Affiliates and (ii) to any sublicensee of a Lead
                  Compound and/or Collaboration  Product in so far as reasonably
                  necessary for such  sublicensee  to develop such Lead Compound
                  and/or Collaboration Product), to use all data and information
                  generated by or on behalf of  Neurocrine in the conduct of the
                  Research  Program,  including  data  relating  to  Hits in the
                  Neurocrine  Proprietary Chemical Library, but only as shall be
                  reasonably  necessary for  Wyeth-Ayerst to conduct research to
                  identify  and  develop  Lead   Compounds   and   Collaboration
                  Products,  provided,  however,  that such license shall become
                  sole  and  exclusive  when a  Compound  is  designated  a Lead
                  Compound in accordance  with Article Six and shall revert to a
                  non-exclusive  license  upon  determination  of  the  Steering
                  Committee or  Wyeth-Ayerst  that such Lead  Compound  will not
                  become a Collaboration Product;

         (f)      during  the term of this  Agreement,  an  exclusive  right and
                  license,  with the  right to  sublicense,  to use all data and
                  information  generated  by or on behalf of  Neurocrine  in the
                  conduct of the  Research  Program  relating to Lead  Compounds
                  and/or  Collaboration  Products in the Neurocrine  Proprietary
                  Chemical  Library,  but only as shall be reasonably  necessary
                  for  Wyeth-Ayerst to conduct  research to identify and develop
                  Lead Compounds and Collaboration Products; and

         (g)      during the term of this Agreement,  a non-exclusive  right and
                  license,   with  no  right  to   sublicense   (except  (i)  to
                  Wyeth-Ayerst's  Affiliates  and (ii) to any  sublicensee  of a
                  Lead  Compound  and/or  Collaboration  Product  in so  far  as
                  reasonably necessary for such sublicensee to develop such Lead
                  Compound and/or Collaboration  Product), to use the Neurocrine
                  Materials  but only to the extent  that such right and license
                  shall be necessary  for  Wyeth-Ayerst  to identify and develop
                  Lead Compounds and Collaboration Products.

3.2      License Grant to Neurocrine.  Wyeth-Ayerst  hereby grants to Neurocrine
         for the term of the  Research  Program  (i) a  non-exclusive  right and
         license, with no right to sublicense, under the Wyeth-Ayerst Technology
         to the  extent  that such  right and  license  shall be  necessary  for
         Neurocrine to perform its obligations under the Research  Program,  and
         (ii) a non-exclusive right and license, with no right to sublicense, to
         use the  Wyeth-Ayerst  Materials but only to the extent that such right
         and  license  shall  be  necessary   for   Neurocrine  to  perform  its
         obligations  under the Research Program and (iii) a nonexclusive  right
         and license to use all data and information generated in the conduct of
         the  Research   Program,   including  data  relating  to  Hits  in  the
         Wyeth-Ayerst  Proprietary  Chemical  Library,  but  only  as  shall  be
         reasonably  necessary for Neurocrine to perform its  obligations  under
         the Research Program.

3.3      Neurocrine   Retained  Rights.   The  exclusive   licenses  granted  to
         Wyeth-Ayerst in Section 3.1 above, shall be subject to the retention by
         Neurocrine  of a  nonexclusive  right  and  license,  with no  right to
         sublicense,  in each case, to the extent  necessary  for  Neurocrine to
         perform its obligations under the Research Program  hereunder.  Subject
         to the licenses  granted to Wyeth-Ayerst in Section 3.1 above,  nothing
         herein  shall be deemed to  restrict  Neurocrine's  right to  otherwise
         exploit the Neurocrine  Technology to develop  products other than Lead
         Compounds and Collaboration  Products  including,  without  limitation,
         Neurocrine's  right  to use and  sublicense  the use of the  Neurocrine
         Transporters  to conduct  selectivity  testing with respect to products
         (other than Lead Compounds and Collaboration  Products) being developed
         by Neurocrine or is corporate partners or sublicensees.

3.4      Prior Agreement.  This Agreement supersedes the Prior Agreement and all
         Compounds which may have been identified under the Prior Agreement will
         be governed solely by the terms and conditions of this Agreement.

3.5      OHSU Agreement.  Patent Rights  licensed to Neurocrine  pursuant to the
         OHSU  Agreement  (the   "Sublicensed   Rights")  are  included  in  the
         Neurocrine Technology licensed to Wyeth-Ayerst hereunder.  Wyeth-Ayerst
         has approved the terms of the OHSU Agreement and the Parties agree that
         the terms of the OHSU Agreement are  consistent  with the terms of this
         Agreement   and  no  conflict   exist  with  respect  to   Neurocrine's
         obligations under this Agreement and Neurocrine's obligations under the
         OHSU Agreement.  Wyeth-Ayerst  will have all of the rights set forth in
         that  agreement  to be  afforded  to  Neurocrine's  sublicensee  of any
         technology licensed thereunder  including,  without limitation,  in the
         event of a termination of the OHSU  Agreement,  the right under Section
         4.03 thereof, to enter into a license,  with respect to the Sublicensed
         Rights, directly with OHSU which license would be on the same terms and
         conditions as the OHSU Agreement. In the event that Wyeth-Ayerst enters
         into such a  license  with  OHSU,  (i)  [***] of any  payments  made by
         Wyeth-Ayerst to OHSU under Paragraph 6.02 thereof  (including  payments
         creditable  against  payments owed under Section 6.02 thereof) and (ii)
         [***] of other payments  thereunder shall in each case be deducted from
         any payments that Wyeth-Ayerst  remains obligated or thereafter becomes
         obligated to make to Neurocrine under this Agreement. Neurocrine agrees
         that it will not  modify or amend the OHSU  Agreement,  insofar  as any
         such  amendment  or  modification  will  have any  impact on any of the
         rights or  obligations  of  Wyeth-Ayerst  under this  Agreement  or any
         agreement entered into between Wyeth-Ayerst and OHSU in accordance with
         this Section 3.5,  without  Wyeth-Ayerst's  prior written consent which
         consent  (i)  may  be  provided   or   withheld  by   Wyeth-Ayerst   in
         Wyeth-Ayerst's  sole  discretion in the case of any  modification  that
         would negatively impact any such rights or obligations of Wyeth-Ayerst,
         including,  without limitation,  any increase in payments to be made by
         Wyeth-Ayerst,   any   increase  in   diligence   obligations,   or  any
         modification of the exclusivity of the Sublicensed Rights, or (ii) will
         not  be  unreasonably  withheld  by  Wyeth-Ayerst  in the  case  of any
         modification  that  would  not  negatively  impact  any such  rights or
         obligations  of  Wyeth-Ayerst.  Neurocrine  further agrees that it will
         promptly  provide  Wyeth-Ayerst  with copies of any notices it receives
         from or gives  to OHSU  pertaining  to any  termination  or  threatened
         termination of the OHSU Agreement.


                                  ARTICLE FOUR
                               STEERING COMMITTEE

4.1      Creation;   Authority.   Immediately  following  the  signing  of  this
         Agreement,  Wyeth-Ayerst  and  Neurocrine  will  establish  a  steering
         committee (the "Steering  Committee")  consisting of at least three (3)
         members from each of Wyeth-Ayerst and Neurocrine with  Wyeth-Ayerst and
         Neurocrine  having  equal  representation  at all times.  The  Steering
         Committee  will  be  responsible   for  monitoring  and  reviewing  the
         implementation  of the Research Plan by the Parties and for determining
         the mechanisms for exchange of  information  and materials  between the
         Parties.  From  time to time,  the  Steering  Committee  may  establish
         subcommittees  to oversee  specific  projects  or  activities  and such
         subcommittees  shall be  constituted  as the Steering  Committee  shall
         determine.  The Steering  Committee will exist until the termination of
         the Research Program unless the Parties otherwise agree in writing.

4.2      Chairperson.  The  chairperson  of  the  Steering  Committee  shall  be
         designated by  Wyeth-Ayerst.  The  chairperson  will be responsible for
         scheduling  meetings of the Steering  Committee,  preparing agendas for
         meetings,  sending to all  Steering  Committee  members  notices of all
         regular meetings and agendas for such meetings.  The chairperson  shall
         appoint a secretary for each meeting who will record the minutes of the
         meeting,  circulate  copies of meeting  minutes to the Parties and each
         Steering  Committee  member promptly  following the meeting for review,
         comment and approval and finalize approved meeting minutes.

4.3      Meetings. The Steering Committee shall meet at least once each calendar
         quarter and may meet at  additional  times as the Parties  shall agree.
         Either Party may call a special  meeting of the Steering  Committee two
         (2) times per year,  on  fifteen(15)  days written  notice to the other
         Party.  The Party  convening a special  meeting  shall send notices and
         agenda  for such  meetings  to the  other  Party  and to each  Steering
         Committee  member.  Meetings will alternate  between the offices of the
         Parties,  unless otherwise agreed, or may be held  telephonically or by
         video-conference.  Members  of the  Committee  shall  have the right to
         participate  in and  vote  at  meetings  by  telephone  and to  vote at
         meetings  by  proxy.  Each  Party  shall be  responsible  for  expenses
         incurred by its  employees  and its members of the  Steering  Committee
         incurred in attending or otherwise  participating in Steering Committee
         meetings.

4.4      Decisions  of the  Committee.  The goal of the  Parties'  collaboration
         shall be the timely  identification  and  development of Lead Compounds
         and Collaboration  Products for  commercialization in the Field of Use.
         All decisions of the Steering Committee shall be made by majority vote,
         with at least one (1) member from each Party voting with the  majority,
         in the exercise of good faith to further the goal of the Collaboration.
         In  the  event  that a  decision  cannot  be  reached  by the  Steering
         Committee,   the  matter  shall  be  referred  to  further  review  and
         resolution by the Chief  Executive  Officer of Neurocrine and President
         of Wyeth-Ayerst Research as set forth in Section 14.1.


                                  ARTICLE FIVE
               COLLABORATIVE RESEARCH PROGRAM AND RESEARCH FUNDING

5.1      Research  Program.  Under the terms and  conditions  set forth  herein,
         Wyeth-Ayerst and Neurocrine will exclusively collaborate in the conduct
         of  a  collaborative   pre-clinical  research  program  (the  "Research
         Program")  to  discover,   identify  and  develop   modulators  of  the
         Neurocrine  Transporters  for the treatment of central  nervous  system
         disorders, [***]. The Research Program will be focused on the screening
         of  the  Wyeth-Ayerst   Proprietary  Chemical  Library  and  Neurocrine
         Proprietary  Chemical  Library and any other library selected by mutual
         agreement  of the Parties for the  identification  of Hits, a medicinal
         chemistry  program for the  development  of Lead  Compound  candidates,
         screening  and testing of Lead  Compound  candidates  to identify  Lead
         Compounds  and  further  preclinical  research  and  screening  of Lead
         Compounds  to  select   Collaboration   Products  for  development  and
         commercialization by Wyeth-Ayerst.

5.2      Term. The initial term of the Research  Program will be three (3) years
         unless earlier terminated in accordance with Article Twelve hereof. The
         initial  term of the  Research  Program  will begin on January 1, 1999.
         Upon the expiration of the initial three (3) year term, the term of the
         Research Program may, upon mutual written agreement of the Parties,  be
         extended for [***] extension terms on  substantially  the same terms as
         those set forth herein.  Notwithstanding  the  foregoing,  in the event
         that at the end of the initial term of the Research Program,  [***] and
         the Steering  Committee or Wyeth-Ayerst has determined that significant
         additional  [***]  should  be  conducted  and  the  Steering  Committee
         determines that such additional [***] justifies  extending the Research
         Program by an additional [***], the Parties will extend the term of the
         Research  Program  [***],  provided,  however,  that in no  event  will
         Wyeth-Ayerst be obligated to fund more than [***] Neurocrine Researcher
         FTEs (at a rate of [***]) during [***].

5.3      Research  Plan.  Within  thirty  (30)  days  following  the  date  this
         Agreement is signed by each of the Parties and on an annual basis on or
         before October 31 of each year thereafter, the Steering Committee shall
         develop and approve,  a research plan and budget for the  collaborative
         Research  Program (the  "Research  Plan").  The  Research  Plan will be
         updated on an annual basis and shall specifically include both detailed
         plans for the following year including staffing levels,  activities and
         estimated  expenditures as well as more general plans for the remaining
         term of the Research Program. The Research Plan may only be modified or
         amended upon the written approval of the Steering Committee.  Except as
         expressly  set  forth  in  Section  5.5  below,  each  Party  shall  be
         responsible for its own costs and expenses incurred in their conduct of
         the Research Program.

5.4      Conduct of the Research Program. Neurocrine and Wyeth-Ayerst shall each
         use Commercially  Reasonable  Efforts to perform its obligations  under
         the  Research   Program  in   accordance   with  the   Research   Plan.
         Notwithstanding,  the  foregoing,  during  the  term  of  the  Research
         Program, Neurocrine shall apply an average of at least [***] Neurocrine
         Researcher  FTEs per  year in  performing  its  obligations  under  the
         Research  Program,  which minimum number of Neurocrine  Researcher FTEs
         shall be increased to [***] upon the successful completion of the first
         [***]  (according  to the  criteria  set forth in Exhibit B, Part 2(a))
         [***] Lead  Compound  (as defined in Exhibit B attached  hereto) and to
         [***] upon the successful  completion of the first [***]  (according to
         the criteria set forth in Exhibit B, Part 2(b)) of [***] Lead Compound,
         provided,  however,  that neither increase shall become effective prior
         to the  beginning  of the [***] of the  Research  Program.  While it is
         anticipated  that Neurocrine and  Wyeth-Ayerst  will each devote to the
         Research  Program  efforts  consistent  with the goals set forth in the
         Research Plan, in no event will  Neurocrine's  failure to devote to the
         Research  Program more than the number of  Neurocrine  Researcher  FTEs
         funded by Wyeth-Ayerst pursuant to Section 5.5 below, in and of itself,
         constitute  a failure  by  Neurocrine  to use  Commercially  Reasonable
         Efforts to conduct the Research Program. In addition,  the Parties have
         agreed that the Research Plan will at all times  allocate to Neurocrine
         sufficient  responsibilities  to  allow  Neurocrine  to  devote  to the
         Research  Program,  the number of Neurocrine  Researcher FTEs funded by
         Wyeth-Ayerst hereunder.

5.5      Funding of the Research Program.

         (a)      Funding  by  Wyeth-Ayerst.  During  the  initial  term  of the
                  Research Program,  Wyeth-Ayerst will provide to Neurocrine the
                  funds in the amount of [***] per calendar quarter, which funds
                  are to be used by Neurocrine solely to fund the conduct of the
                  Research  Program by [***]  Neurocrine  Researcher  FTEs.  The
                  funding  amount set forth in the preceding  sentence  shall be
                  increased  to [***] per calendar  quarter upon the  successful
                  completion  of the first [***]  (according to the criteria set
                  forth in Exhibit B, Part 2(a)) [***] Lead Compound which funds
                  are to be used by Neurocrine solely to fund the conduct of the
                  Research  Program by [***]  Neurocrine  Researcher FTEs and to
                  [***] per calendar  quarter upon the successful  completion of
                  the [***]  (according  to the criteria set forth in Exhibit B,
                  Part 2(b)) of [***] Lead Compound  [***] which funds are to be
                  used by Neurocrine  solely to fund the conduct of the Research
                  Program  by  [***]  Neurocrine   Researcher  FTEs,   provided,
                  however,  that (i) neither  increase  shall  become  effective
                  prior to [***] of the  Research  Program  and (ii)  subject to
                  clause (i) above, each such increase shall become effective on
                  the first day of the calendar  quarter  following the calendar
                  quarter in which the event resulting in such increase  occurs.
                  Wyeth-Ayerst  will  provide  the  funding  set  forth  in this
                  Section  5.5(a) to  Neurocrine  [***]  during  the term of the
                  Research  Program,  provided  however,  that the first payment
                  will be due on  [***]  business  day  following  the  date the
                  Parties shall have both signed this Agreement.

         (b)      Reporting  and  Reconciliation.  Within thirty (30) days after
                  the  end of  each  calendar  quarter  during  the  term of the
                  Research  Program,  Neurocrine  will provide to Wyeth-Ayerst a
                  report setting forth the number of Neurocrine  Researcher FTEs
                  devoted to the Research Program in such calendar quarter along
                  with their  names and  titles.  In the event  that  Neurocrine
                  shall, in any calendar  quarter,  devote to the conduct of the
                  Research   Program   fewer  than  the  number  of   Neurocrine
                  Researcher FTEs funded by  Wyeth-Ayerst  for the such calendar
                  quarter as required under Section 5.4 hereof, Neurocrine shall
                  in  good  faith  endeavor  to  devote,  at  its  own  expense,
                  additional  Neurocrine  Researcher  FTEs to the conduct of the
                  Research  Program in subsequent  calendar  quarters to make up
                  for the shortfall. If, despite Neurocrine's good faith efforts
                  to make up any  shortfall in number of  Neurocrine  Researcher
                  FTEs devoted to the Research  Program versus the funded number
                  of Neurocrine  Researcher FTEs set forth in Section 5.5, it is
                  determined at the end of the term of the Research Program that
                  Neurocrine  has,  over  the  life  of  the  Research  Program,
                  utilized  less than the number of Neurocrine  Researcher  FTEs
                  funded by  Wyeth-Ayerst  hereunder,  Neurocrine  shall  within
                  thirty   (30)  days   after  such   determination   refund  to
                  Wyeth-Ayerst  the excess Research  Program funding provided to
                  Neurocrine  under Section 5.5(a) above,  which refund shall be
                  equal to [***]  multiplied by the  difference  between (x) the
                  number (in the aggregate) of Neurocrine  Researcher  FTEs that
                  were  funded  by  Wyeth-Ayerst   [***]  Research   Program  in
                  accordance  with  Section  5.5 and (y) the  actual  number  of
                  Neurocrine  Researcher  FTEs,  in  the  aggregate,  that  were
                  devoted to the Research  Program [***] Research  Program.  For
                  example, if the number of Neurocrine Researcher FTEs funded by
                  Wyeth-Ayerst  [***] of the  Research  Program  was  [***]  and
                  Neurocrine, in fact, only utilized [***] Neurocrine Researcher
                  FTEs [***] of the Research  Program,  Neurocrine  would refund
                  [***] to Wyeth-Ayerst.

         (c)      Records and Audits.  During the term of the  Research  Program
                  and for a period  of three (3)  years  thereafter,  Neurocrine
                  shall keep and maintain  accurate and complete records showing
                  the time devoted and activities  performed by each  Neurocrine
                  Researcher in performing  Neurocrine's  obligations  under the
                  Research Program in sufficient  detail such that the number of
                  Neurocrine  Researcher  FTEs applied to the  Research  Program
                  during  each  calendar   quarter  thereof  can  be  accurately
                  determined.  Upon fifteen (15) days prior written  notice from
                  Wyeth-Ayerst, Neurocrine shall permit an independent certified
                  public  accounting  firm  of  nationally  recognized  standing
                  selected  by   Wyeth-Ayerst   and  reasonably   acceptable  to
                  Neurocrine,  to  examine  the  relevant  books and  records of
                  Neurocrine and its  Affiliates as may be reasonably  necessary
                  to  verify  the   accuracy   of  the  reports   submitted   to
                  Wyeth-Ayerst  under  Section  5.5(b)  hereof and the number of
                  Neurocrine  Researcher  FTEs  applied  to the  performance  of
                  Neurocrine's   obligations  under  the  Research  Program.  An
                  examination  under this  Section  5.5(c)  shall not occur more
                  than once in any calendar year and no such  examination may be
                  conducted  more than eighteen (18) months after the expiration
                  or earlier termination of the Research Program. The accounting
                  firm shall provide both Neurocrine and  Wyeth-Ayerst a written
                  report disclosing  whether the reports submitted by Neurocrine
                  are correct or incorrect and the specific  details  concerning
                  any  discrepancies.  No other information shall be provided to
                  Wyeth-Ayerst.

5.6      Invention Assignment  Agreements.  Each Neurocrine  Researcher and each
         scientist of  Wyeth-Ayerst  conducting  the Research  Program will have
         executed  Neurocrine's or Wyeth-Ayerst's,  as the case may be, standard
         non-disclosure and invention assignment agreement.

5.7      Reporting and Disclosure.

         (a)      Reports.  Prior  to each  quarterly  meeting  of the  Steering
                  Committee,  Neurocrine and Wyeth-Ayerst  will each provide the
                  other with  written  copies of all  materials  they  intend to
                  present at the Steering  Committee meeting plus, to the extent
                  not set forth in the Steering Committee  materials,  a written
                  report  summarizing  any other  material data and  information
                  arising out of the  conduct of the  Research  Program.  In the
                  event that  after  receipt of any such  report,  either  Party
                  shall  request  additional  data or  information  relating  to
                  Research  Program data or  Collaboration  Technology  licensed
                  hereunder,  the  Party  to whom  such  request  is made  shall
                  promptly  provide to the other Party such data or  information
                  that such  Party  reasonably  believes  is  necessary  for the
                  continued conduct of the Research Program.

         (b)      Quarterly Meetings.  At the quarterly meetings of the Steering
                  Committee,   Wyeth-Ayerst   and  Neurocrine   will  review  in
                  reasonable  detail (i) all data and  information  generated in
                  the conduct of the  Research  Program by each Party,  and (ii)
                  all Collaboration  Technology  licensed hereunder developed by
                  the Parties.

         (c)      Disclosure.  During  the  term of the  Research  Program,  the
                  Parties  will  promptly  disclose  to one  another  all  data,
                  information,  inventions,  techniques and discoveries (whether
                  patentable  or not) arising out of the conduct of the Research
                  Program  and  all   inventions,   techniques  and  discoveries
                  (whether   patentable  or  not)   included  in   Collaboration
                  Technology licensed hereunder.

5.8      Data.

         (a)      Neurocrine  Data. All data and information  arising out of the
                  Research Program which relates  specifically to Compounds from
                  the Neurocrine  Proprietary  Chemical Library will be owned by
                  Neurocrine,  will be Neurocrine Confidential  Information and,
                  subject to the licenses  granted to  Wyeth-Ayerst,  if any, as
                  set forth herein, may be used by Neurocrine for any purpose.

         (b)      Wyeth-Ayerst Data. All data and information arising out of the
                  Research Program which relates  specifically to Compounds from
                  the Wyeth-Ayerst Proprietary Chemical Library will be owned by
                  Wyeth-Ayerst,  will be Wyeth-Ayerst  Confidential  Information
                  and, subject to the licenses granted to Neurocrine, if any, as
                  set forth herein, may be used by Wyeth-Ayerst for any purpose.

         (c)      Other Research Program Data. All data and information  arising
                  out of the Research  Program which is not  Neurocrine  Data or
                  Wyeth-Ayerst  Data as set forth in (a) and (b) above,  will be
                  jointly  owned by the Parties  and will be Joint  Confidential
                  Information  and,  subject  to the  licenses  granted or to be
                  granted  by one  Party  to the  other,  if any,  as set  forth
                  herein, may be used by the Parties for any purpose.
         (d)      Wyeth-Ayerst     Research,     Clinical     Development    and
                  Commercialization  Data. All data and information  arising out
                  of Wyeth-Ayerst's research and preclinical development of Lead
                  Compounds and/or Collaboration  Products after the term of the
                  Research  Program and all data and information  arising out of
                  the   clinical    development   and    commercialization    of
                  Collaboration   Products  by   Wyeth-Ayerst   will  belong  to
                  Wyeth-Ayerst   and   shall   be   Wyeth-Ayerst    Confidential
                  Information.

5.9      Materials.

         (a)      Research Program Materials. During the term of this Agreement,
                  upon request by either Party, the Party to whom the request is
                  made will promptly  provide to the other Party such quantities
                  of Research Program Materials as shall be reasonably available
                  in excess of its own needs for such  other  Party to carry out
                  its respective responsibilities under this Agreement.  Subject
                  to the licenses set forth in Article Three, each Party may use
                  the Research  Program  Materials  created or developed by such
                  Party for any purpose.

         (b)      Neurocrine  Materials.  During  the  term of  this  Agreement,
                  Neurocrine  will supply to Wyeth-Ayerst  Neurocrine  Materials
                  reasonably  (both  in  quantity  and  identity)  requested  by
                  Wyeth-Ayerst   provided  (i)  such  Neurocrine  Materials  are
                  reasonably  and readily  available to  Neurocrine in excess of
                  Neurocrine's  own  requirements,   and  (ii)  supply  of  such
                  Neurocrine  Materials will not, in Neurocrine's sole judgment,
                  (A)  conflict  with  Neurocrine's  internal  or  collaborative
                  research  programs,  (B) conflict with  Neurocrine's  internal
                  policies regarding such materials or (C) violate any agreement
                  to which  Neurocrine  is a  party.  Any  Neurocrine  Materials
                  provided to  Wyeth-Ayerst  hereunder  together with  materials
                  derived therefrom thereof (i) may only be used by Wyeth-Ayerst
                  and  Wyeth-Ayerst's  permitted  sublicensees in the conduct of
                  the  Research   Program   and/or  in  the   discovery   and/or
                  development of Lead Compounds and/or  Collaboration  Products,
                  (ii) may not be  supplied to Third  Parties,  other than Third
                  Parties that, with the approval of the Steering Committee, are
                  under contract with one of the Parties to perform  services in
                  support of the Research Program,  without  Neurocrine's  prior
                  written  consent  which  can be  withheld  for any  reason  in
                  Neurocrine's  sole  discretion and (iii) will, at Neurocrine's
                  option and at  Neurocrine's  request be returned to Neurocrine
                  or destroyed.  The provision of Neurocrine Materials hereunder
                  will not  constitute  any grant,  option or license  under any
                  Neurocrine  Patent  Rights,  except  as  expressly  set  forth
                  herein.

         (c)      Wyeth-Ayerst  Materials.  During  the  term  of  the  Research
                  Program,  Wyeth-Ayerst will supply to Neurocrine  Wyeth-Ayerst
                  Materials reasonably (both in quantity and identity) requested
                  by Neurocrine,  provided that (i) such Wyeth-Ayerst  Materials
                  are   reasonably   and   readily   available   in   excess  of
                  Wyeth-Ayerst's   own  requirement  and  (ii)  supply  of  such
                  Wyeth-Ayerst owned Materials will not, in Wyeth-Ayerst's  sole
                  judgment,   (A)  conflict  with  Wyeth-Ayerst's   internal  or
                  collaborative    research   programs,    (B)   conflict   with
                  Wyeth-Ayerst's  internal policies  regarding such materials or
                  (C) violate any  agreement to which  Wyeth-Ayerst  is a party.
                  Any Wyeth-Ayerst  Materials  provided to Neurocrine  hereunder
                  together with any materials  derived therefrom (i) may only be
                  used by  Neurocrine  in the conduct of the  Research  Program,
                  (ii)   may  not  be   supplied   to  Third   Parties   without
                  Wyeth-Ayerst's prior written consent which can be withheld for
                  any reason in  Wyeth-Ayerst's  sole discretion and (iii) will,
                  at  Wyeth-Ayerst's  option and at Wyeth-Ayerst's  request,  be
                  returned  to  Wyeth-Ayerst  or  destroyed.  The  provision  of
                  Wyeth-Ayerst  Materials  hereunder  will  not  constitute  any
                  grant, option or license under any Wyeth-Ayerst Patent Rights,
                  except as expressly set forth herein.


                                   ARTICLE SIX
                           SELECTION OF LEAD COMPOUNDS
                           AND COLLABORATION PRODUCTS

6.1      Selection  of Lead  Compounds  During  Term of Research  Program.  Lead
         Compounds may be selected by the Steering  Committee during the term of
         the Research Program from Hits in the Neurocrine  Proprietary  Chemical
         Library, Wyeth-Ayerst Proprietary Chemical Library or any other library
         the  Parties  shall  agree to screen in  connection  with the  Research
         Program.  Additionally,  if any Compound in the Neurocrine  Proprietary
         Chemical Library is identified as a Hit during the term of the Research
         Program,  Wyeth-Ayerst  may, upon written notice to Neurocrine,  select
         such Compound as a Lead Compound at any time during [***].

6.2      Selection  of Lead  Compounds  After  Term of  Research  Program.  Lead
         Compounds  may be  selected  by  Wyeth-Ayerst  after  the  term  of the
         Research  Program  from  Compounds  in  the  Wyeth-Ayerst   Proprietary
         Chemical  Library  or any other  library  Wyeth-Ayerst  shall  elect to
         screen  in  connection  with  the  development  of Lead  Compounds  and
         Collaboration    Products   using   the    Collaboration    Technology.
         Notwithstanding the foregoing,  except as expressly provided in Section
         6.1 above, in no event will  Wyeth-Ayerst be entitled after the term of
         the  Research  Program  to  select  Compounds  from  Compounds  in  the
         Neurocrine   Proprietary   Chemical   Library  as  Lead   Compounds  or
         Collaboration Products.

6.3      Selection  of  Collaboration   Products.  Lead  Compounds  will  become
         Collaboration  Products  upon  Wyeth-Ayerst's  decision  that  the Lead
         Compound is a suitable clinical  candidate or Wyeth-Ayerst  shall elect
         to file an IND  with  respect  to such  Lead  Compound.  Wyeth-Ayerst's
         determination  that a Lead  Compound is a suitable  clinical  candidate
         will be based on its  preclinical  profile  and  competitive  and other
         commercial considerations.

6.4      Designation of Lead  Compounds and  Collaboration  Products.  It is the
         Parties'  intention  that the licenses set forth in Articles  Three and
         Twelve and all rights  granted by either Party  hereunder be limited to
         Lead Compounds and  Collaboration  Products and neither Party grants to
         the  other  any right or  license  in or to Patent  Rights or any other
         rights a Party  may have in its  Proprietary  Chemical  Library  or any
         Compounds included therein that are not Lead Compounds or Collaboration
         Products.  The  Parties  agree  that  during  the term of the  Research
         Program (a) a compound may only be  designated a Lead Compound upon the
         determination of the Steering Committee,  as recorded in the minutes of
         a Steering  Committee  meeting or by  written  consent of the  Steering
         Committee, that such compound meets the criteria set forth herein for a
         Lead  Compound  and  (b) a Lead  Compound  may  only  be  designated  a
         Collaboration  Product  upon  Wyeth-Ayerst's   written  notice  to  the
         Steering  Committee that  Wyeth-Ayerst has elected to initiate clinical
         development  with respect to the Lead  Compound.  After the term of the
         Research Program, a compound will only be designated a Lead Compound or
         a  Collaboration  Product  hereunder upon timely written notice (within
         sixty (60) days after the  determination  or election  set forth below)
         from  Wyeth-Ayerst  to Neurocrine  describing  the compound and setting
         forth  Wyeth-Ayerst's   determination  that  such  compound  meets  the
         criteria  set  forth  herein  for a  Lead  Compound  or  Wyeth-Ayerst's
         election to initiate clinical  development of a Lead Compound elevating
         the Lead Compound to Collaboration Product status hereunder.



                                 ARTICLE SEVEN
                DEVELOPMENT, MANUFACTURING AND COMMERCIALIZATION

7.1      Wyeth-Ayerst  Development.  Wyeth-Ayerst will,  directly and/or through
         Third  Parties,  use  Commercially  Reasonable  Efforts to complete the
         preclinical development, conduct, fund and make all decisions regarding
         the clinical development of Collaboration  Products.  Wyeth-Ayerst will
         have complete control,  authority and responsibility for the regulatory
         strategies  adopted for the clinical  development of all  Collaboration
         Products and will own all Regulatory  Filings and Regulatory  Approvals
         relating to any Lead Compound or Collaboration Product.

7.2      Progress Reports. After the end of the Research Program,  Wyeth-Ayerst,
         within sixty (60) days after each June 30 and December 31, will provide
         Neurocrine  with a report  summarizing  the  status  of  Wyeth-Ayerst's
         clinical development  activities during the six (6) month period ending
         on such  June 30 or  December  31,  as  applicable,  for  Collaboration
         Products then in active  development by Wyeth-Ayerst  and summarize the
         development plans for Collaboration  Products for the following six (6)
         month period, provided, however, that Wyeth-Ayerst's failure to achieve
         any of the goals or plans set forth in any such  summary  shall not, in
         and of itself, constitute a failure by Wyeth-Ayerst to use Commercially
         Reasonable Efforts to develop Collaboration Products hereunder.

7.3      Manufacturing.  Wyeth-Ayerst shall use Commercially  Reasonable Efforts
         to  manufacture   Collaboration   Products,   directly  and/or  through
         contracted  Third Parties for sale in those  countries of the Territory
         where such Collaboration Products have received Regulatory Approval.

7.4      Commercialization of Collaboration  Products.  Wyeth-Ayerst in its sole
         discretion will make all decisions regarding the  commercialization and
         sales and marketing of Collaboration Products and will use Commercially
         Reasonable  Efforts to  commercialize  Collaboration  Products in those
         countries of the world where such Collaboration  Products have received
         Regulatory Approval. The use of Commercially  Reasonable Efforts by any
         Affiliate or sublicensee of Wyeth-Ayerst to commercialize Collaboration
         Products in a country  shall satisfy  Wyeth-Ayerst's  obligation to use
         Commercially  Reasonable  Efforts to commercialize  such  Collaboration
         Product in such country.

7.5      Co-Promotion. On a Collaboration Product by Collaboration Product basis
         at  the  time  of  NDA  filing,   if  Neurocrine  can   demonstrate  to
         Wyeth-Ayerst's  reasonable  satisfaction that Neurocrine has commercial
         presence in a United States or Canadian  market  segment not covered by
         Wyeth-Ayerst or, in Wyeth-Ayerst's  view, not sufficiently  covered and
         capability  to  promote  such  Collaboration  Product  in  such  market
         segment,  Wyeth-Ayerst and Neurocrine will discuss[***] co-promote such
         Collaboration  Product in the United States and Canada.  If the Parties
         agree that it would be in the commercial  best interests of the Parties
         for  Wyeth-Ayerst  and Neurocrine to so co-promote  such  Collaboration
         Product, the Parties will, [***], use good faith efforts to negotiate a
         co-promotion agreement setting forth the rights and obligations of each
         Party,  including,  without  limitation,  payments to be made by either
         Party  to  the  other  Party  and   responsibility  for  marketing  and
         promotional expenses. If, (i) [***],  Neurocrine either fails to notify
         Wyeth-Ayerst of its desire to co-promote such Collaboration  Product or
         fails to demonstrate to  Wyeth-Ayerst's  reasonable  satisfaction  that
         Neurocrine  has the  required  commercial  presence and  capability  to
         promote such Collaboration  Product,  or (ii) the Parties fail to enter
         into a co-promotion  agreement by the end of the [***] period described
         above in this Section 7.5,  Wyeth-Ayerst  shall  thereafter be free, at
         its sole  election,  to enter into a  co-promotion  agreement  with any
         Third Party with respect to such Collaboration Product.


                                  ARTICLE EIGHT
                                  LICENSE FEES

8.1      License  Fees.  Each of the  following  License Fees will be payable to
         Neurocrine one-time only within thirty (30) days following confirmation
         by the Steering Committee that the specified event has occurred.



                                      Event                                          Payment
                                                                                   
  
             Validation  of [***] model of  Neurodegeneration  [***] (such model     [***]     
             and criteria for  validation  to be selected and agreed upon by the
             Steering  Committee as soon as practicable after the first Steering
             Committee meeting)

             Completion of screening of [***] compounds selected by the Steering     [***]     
             Committee  from  the  Neurocrine   Proprietary   Chemical  Library,
             Wyeth-Ayerst   Proprietary   Chemical  Library  and/or  some  other
             library(ies)  selected by the Steering  Committee  for the first to
             complete  of  [***]  using   Neurocrine's   novel  High  Throughput
             Screening ("HTS")  technology,  provided,  however,  that the [***]
             compounds  selected by the Steering  Committee  must all be readily
             available to  Neurocrine  in 96 well plates  suitable for screening
             and within a timeframe  that will not  materially  or  unreasonably
             delay Neurocrine's screening efforts

             The  later  to  occur  of (i)  completion  of  screening  of  [***]     [***]     
             compounds  selected by the Steering  Committee  from the Neurocrine
             Proprietary  Chemical Library,  Wyeth-Ayerst  Proprietary  Chemical
             Library  and/or some other  library(ies)  selected by the  Steering
             Committee  for the second to complete  of [***] using  Neurocrine's
             HTS technology and (ii) the [***] anniversary of the Effective Date

             [***]  target  validation  of [***] in a model [***] (such mode and     [***]     
             criteria  for  validation  to be  selected  and agreed  upon by the
             Steering  Committee as soon as practicable after the first Steering
             Committee meeting)

             [***]  validation  of [***] in a model (such model and criteria for     [***]
             validation to be selected and agreed upon by the Steering Committee
             as soon as practicable after the first Steering Committee meeting)

             [***] target  validation of [***] in an appropriate model for [***]     [***]
             (such model and criteria for  validation  to be selected and agreed
             upon by the  Steering  Committee as soon as  practicable  after the
             first Steering Committee meeting)

             [***]  validation of the [***] in an  appropriate  model for [***],     [***]    
             (such model and criteria for validation and disease  category to be
             selected  and  agreed  upon by the  Steering  Committee  as soon as
             practicable after the first Steering Committee meeting)

        
         For the  purposes  of the  foregoing,  Neurocrine's  HTS  for  activity
         against [***] will be deemed `complete' when [***]compounds selected by
         the Steering  Committee  have been screened for activity  against [***]
         and  Neurocrine  has prepared and  delivered  to  Wyeth-Ayerst  a final
         report  setting forth the results.  Upon the  achievement of a Licensee
         Fee  triggering  event for [***],  any License  Fees  relating to prior
         triggering  events for [***] which have not been paid,  shall be deemed
         payable.

8.2      Additional License Fees. The following  additional License Fees will be
         payable  to  Neurocrine   [***]  only   regardless  of  the  number  of
         Collaboration   Products  and  the  number  of  indications   for  each
         Collaboration Product developed and commercialized.



                                                                                     Additional
                            Event                                                   License Fee
                                                                                         
             Filing, by Wyeth-Ayerst, of an IND in the United States                 [***]
             permitting the clinical study of [***]

             Filing, by Wyeth-Ayerst, of an IND in the United States                 [***]
             permitting the clinical study of [***]

             Filing, by Wyeth-Ayerst, of an IND in the United States                 [***]
             permitting the clinical study of [***]

             Filing, by Wyeth-Ayerst, of an IND in the United States                 [***]
             permitting the clinical study of [***]

             Achievement, by Wyeth-Ayerst, of ICE for the [***]                      [***]

             Achievement, by Wyeth-Ayerst, of ICE for the [***]                      [***]

             Achievement, by Wyeth-Ayerst, of ICE for the [***]                      [***]

             Achievement, by Wyeth-Ayerst, of ICE for the [***]                      [***]

             Initiation, by Wyeth-Ayerst, of a Pivotal Trial to study                [***]
             the [***]

             Initiation, by Wyeth-Ayerst, of a Pivotal Trial to study                [***]
             the [***]

             Initiation, by Wyeth-Ayerst, of a Pivotal Trial to study                [***]
             the [***]

             Initiation, by Wyeth-Ayerst, of a Pivotal Trial to study                [***]
             the [***]

             Filing, by Wyeth-Ayerst,  of an NDA in the United States,               [***]
             and  acceptance,  by the  FDA,  of such  NDA  for  filing
             seeking  Regulatory  Approval in the United States of the
             [***]

             Filing, by Wyeth-Ayerst,  of an NDA in the United States,               [***]
             and  acceptance,  by the  FDA,  of such  NDA for  filing,
             seeking  Regulatory  Approval in the United States of the
             [***]

             Filing, by Wyeth-Ayerst,  of an NDA in the United States,               [***]    
             and  acceptance,  by the  FDA,  of such  NDA for  filing,
             seeking  Regulatory  Approval in the United States of the
             [***]

             Filing,  by Wyeth-Ayerst,  of an NDA in the United States               [***]     
             and  acceptance,  by the  FDA,  of such  NDA for  filing,
             seeking  Regulatory  Approval in the United States of the
             [***]

             Filing,  by  Wyeth-Ayerst,  of an NDA in Europe (either a               [***]     
             centralized  filing  or filing in at least one (1) of the
             European Major Market Countries),  and acceptance, by the
             applicable European Regulatory  Authorities,  of such NDA
             for  filing,  seeking  Regulatory  Approval in Europe (or
             such European country) of the [***]

             Filing,  by  Wyeth-Ayerst,  of an NDA in Europe (either a               [***]     
             centralized  filing  or filing in at least one (1) of the
             European Major Market Countries),  and acceptance, by the
             appropriate European Regulatory Authorities,  of such NDA
             for filing seeking Regulatory Approval in Europe (or such
             European country) of the [***]

             Filing,  by  Wyeth-Ayerst,  of an NDA in Europe (either a               [***]     
             centralized  filing  or filing in at least one (1) of the
             European Major Market Countries),  and acceptance, by the
             applicable European Regulatory  Authorities,  of such NDA
             for filing seeking Regulatory Approval in Europe (or such
             European country) of the [***]



             Filing,  by  Wyeth-Ayerst,  of an NDA in Europe (either a               [***]          
             centralized  filing  or filing in at least one (1) of the
             European Major Market Countries),  and acceptance, by the
             applicable European Regulatory  Authorities,  of such NDA
             for filing seeking Regulatory Approval in Europe (or such
             European country) of the [***]

             United States Regulatory Approval granted to Wyeth-Ayerst               [***]
             for the [***]

             United States Regulatory Approval granted to Wyeth-Ayerst               [***]
             for the [***]

             United States Regulatory Approval granted to Wyeth-Ayerst               [***]
             for the [***]

             United States Regulatory Approval granted to Wyeth-Ayerst               [***]
             for the [***]

             European  (either  centralized  or in at  least  one  (1)               [***]            
             European  Major  Market  Country)   Regulatory   Approval
             granted to Wyeth-Ayerst for the [***]


             European  (either  centralized  or in at  least  one  (1)               [***]          
             European  Major  Market  Country)   Regulatory   Approval
             granted to Wyeth-Ayerst for the [***]

             European  (either  centralized  or in at  least  one  (1)               [***]     
             European  Major  Market  Country)   Regulatory   Approval
             granted to Wyeth-Ayerst for the [***]

             European  (either  centralized  or in at  least  one  (1)               [***]          
             European  Major  Market  Country)   Regulatory   Approval
             granted to Wyeth-Ayerst for the [***]


         Any additional License Fees paid for a Collaboration Product which does
         not  achieve  Regulatory  Approval  shall be fully  creditable  against
         Additional License Fees that may be payable for Collaboration  Products
         subsequently  developed  [***].  No  additional  License  Fee  shall be
         payable  for the  third  or any  subsequent  Collaboration  Product  to
         achieve the specified event.


                             ARTICLE NINE
                               ROYALTIES

9.1      Royalty Rates.  Wyeth-Ayerst  will pay to Neurocrine,  Royalties,  on a
         Collaboration  Product by Collaboration  Product basis, which Royalties
         shall be calculated using the following formula:

                  [***]
                           where,

                           A equals [***] of Wyeth-Ayerst's worldwide Net Sales
                           of such  Collaboration  Product,  which,  during  the
                           calendar year in question, are [***]

                           B equals [***] of Wyeth-Ayerst's  worldwide Net Sales
                           of such  Collaboration  Product,  which,  during  the
                           calendar year in question, [***]; and

                           C equals [***] of Wyeth-Ayerst's  worldwide Net Sales
                           of such  Collaboration  Product,  which,  during  the
                           calendar year in question, are [***].

         By way of example  only,  if,  during a given year,  Wyeth-Ayerst,  its
         Affiliates and  sublicensees  [***] the royalty payable by Wyeth-Ayerst
         to Neurocrine during such year would be calculated as follows:

                  [***]

         Neurocrine acknowledges and agrees that nothing in this Agreement shall
         be construed as  representing  an estimate or  projection of either (i)
         the number of  Collaboration  Products that will or may be successfully
         developed and/or  commercialized  estimate or (ii) anticipated sales or
         the actual value of the Neurocrine Technology, any Lead Compound or any
         Collaboration  Product and that the  figures set forth in this  Section
         9.1 or  elsewhere  in  this  Agreement  or  that  have  otherwise  been
         discussed by the Parties are merely  intended to define  Wyeth-Ayerst's
         royalty  obligations to Neurocrine in the event such sales  performance
         is achieved.  WYETH-AYERST MAKES NO REPRESENTATION OR WARRANTY,  EITHER
         EXPRESS OR IMPLIED, THAT IT WILL BE ABLE TO SUCCESSFULLY DEVELOP AND/OR
         COMMERCIALIZE ANY COLLABORATION PRODUCTS OR, IF COMMERCIALIZED, THAT IT
         WILL  ACHIEVE  ANY  PARTICULAR   SALES  LEVEL  OF  SUCH   COLLABORATION
         PRODUCT(S).

9.2      Royalty Adjustments.  Royalties on a Collaboration  Product are subject
         to  reductions  and  adjustments  as a result of certain  events as set
         forth  below;  provided,  however,  in no  event  will  Royalties  on a
         Collaboration  Product  in  any  country  be  [***]  by  reason  of the
         adjustments set forth below.

         (a)      Royalty Adjustment for Unpatented Products. If, during a given
                  calendar  quarter,  a  Collaboration  Product is an Unpatented
                  Product  in one or  more  countries,  the  Royalties  will  be
                  payable to Neurocrine for the Net Sales of such  Collaboration
                  Product in such  country(ies)  during such calendar quarter at
                  [***] of the  royalty  rate(s) set forth in Section 9.1 above.
                  To calculate the Unpatented Product Royalties, [***]. The fact
                  that a Collaboration  Product is an Unpatented  Product in one
                  country  during  any  calendar  quarter  shall not result in a
                  reduction of the royalty  rate used to  calculate  the Royalty
                  payable  for  sales of  Collaboration  Products  in any  other
                  country during such calendar quarter.

        (b)       Competition.  If Competition  exists,  during a given calendar
                  quarter with respect to a Collaboration  Product in a country,
                  the royalty rate(s) used to calculate the Royalties payable to
                  Neurocrine for the sale of such Collaboration  Product in such
                  country during such calendar quarter will [***] of the royalty
                  rate(s)  set forth in Section  9.1  above.  To  calculate  the
                  Royalties when  Competition  exists in one or more  countries,
                  [***].  The existence of Competition in one country during any
                  calendar  quarter  shall  not  result  in a  reduction  of the
                  royalty rate used to calculate  the Royalty  payable for sales
                  of  Collaboration  Products in any other  country  during such
                  calendar   quarter.   If  at  the  time  of  determining   any
                  Competition adjustments, applicable IMS International data (or
                  such other data as may be mutually  agreed by the Parties) for
                  such  time  period  is  unavailable,  Wyeth-Ayerst  may make a
                  reasonable  estimate  thereof  based  on prior  available  IMS
                  International  data (or  such  other  data as may be  mutually
                  agreed by the Parties) and  calculate the  applicable  Royalty
                  based on such estimate, and any difference in Royalty payments
                  made by  Wyeth-Ayerst  based  on  such  estimate  and  Royalty
                  payments  based  on  actual  data,  once  available,  will  be
                  accounted for by an adjustment  payment by Wyeth-Ayerst at the
                  time the next quarter Royalty payment is made or an adjustment
                  credit against  Wyeth-Ayerst's future Royalty obligations,  as
                  the case may be.

9.3      Term of Royalty.  Royalties will be payable on a country by country and
         Collaboration Product by Collaboration Product basis until the later of
         (i) the last to expire, in such country,  of the Patent Rights included
         within the Collaboration Technology,  [***] or (ii) with respect to the
         sale of such Collaboration  Product in countries of the European Union,
         [***] from First Commercial Sale of such  Collaboration  Product in the
         European  Union and,  with  respect  to the sale of such  Collaboration
         Product in any country outside of the European Union,  [***] from First
         Commercial Sale of such Collaboration Product in such country. Upon the
         expiration of Wyeth-Ayerst's  obligation to pay Royalties to Neurocrine
         hereunder with respect to a Collaboration  Product,  Wyeth-Ayerst shall
         have a fully paid,  irrevocable,  exclusive  and  unrestricted  license
         under the Collaboration Technology to make, have made, use, sell, offer
         to sell and import such Collaboration Product.

9.4      Reports and Payments.

         (a)      Cumulative  Royalties.  The obligation to pay Royalties  under
                  this  Article Nine shall be imposed only once (i) with respect
                  to any sale of the same unit of Collaboration Product and (ii)
                  with  respect  to  a  single  unit  of  Collaboration  Product
                  regardless of how many Valid Claims of Patent Rights  included
                  in the Collaboration Technology would, but for this Agreement,
                  be  infringed  by  the  making,   using  or  selling  of  such
                  Collaboration Product.

        (b)       Statements  and  Payments.   Wyeth-Ayerst   shall  deliver  to
                  Neurocrine  within  sixty  (60)  days  after  the  end of each
                  calendar  quarter,  a  report  certified  by  Wyeth-Ayerst  as
                  accurate to the best of its ability based on information  then
                  available to  Wyeth-Ayerst,  setting  forth for such  calendar
                  quarter the following information on a country-by-country  and
                  Collaboration  Product by Collaboration Product basis: (i) Net
                  Sales of such Collaboration  Product in such country, (ii) the
                  basis for any  adjustments to the Royalty payable for the sale
                  of such  Collaboration  Product in such  country and (iii) the
                  Royalty  due  hereunder  for the  sale  of such  Collaboration
                  Product in such country. The total Royalty due for the sale of
                  Collaboration  Products during such calendar  quarter shall be
                  remitted at the time such report is made.

        (c)       Taxes and Withholding.  All payments under this Agreement will
                  be made without any deduction or withholding for or on account
                  of any tax unless such deduction or withholding is required by
                  applicable  law or  regulations.  If the  paying  Party  is so
                  required  to deduct or withhold  such Party will (i)  promptly
                  notify the other  Party of such  requirement,  (ii) pay to the
                  relevant  authorities  the full amount required to be deducted
                  or withheld promptly upon the earlier of determining that such
                  deduction or withholding is required or receiving  notice that
                  such amount has been assessed  against the other Party,  (iii)
                  promptly  forward to the other Party an  official  receipt (or
                  certified copy) or other documentation  reasonably  acceptable
                  to the other Party evidencing such payment to the authorities.
                  In case the other Party can not take a full credit against its
                  tax liability for the  withholding tax deducted or withheld by
                  the paying  Party,  then such other Party may propose a change
                  to the then  current  arrangement  with respect to the flow of
                  moneys  under this  Agreement  in order to reduce or eliminate
                  the  extra  cost  for  any  Party  and  the  Parties,  with no
                  obligation as to outcome,  shall discuss such proposal in good
                  faith.

         (d)      Currency. All amounts payable and calculations hereunder shall
                  be in United States dollars. As applicable, Net Sales shall be
                  translated  into  United  States  dollars in  accordance  with
                  Wyeth-Ayerst's  customary  and usual  translation  procedures,
                  consistently applied.

        (e)       Maintenance  of  Records;  Audit.  For a period  of three  (3)
                  years,   Wyeth-Ayerst  shall  maintain  and  shall  cause  its
                  Affiliates and sublicensees to maintain  complete and accurate
                  books and records in connection with the sale of Collaboration
                  Products  hereunder,   as  necessary  to  allow  the  accurate
                  calculation  of Royalties due hereunder  including any records
                  required to calculate any Royalty adjustments hereunder.  Once
                  per calendar year Neurocrine shall have the right to engage an
                  independent  accounting  firm acceptable to  Wyeth-Ayerst,  at
                  Neurocrine's expense, which shall have the right to examine in
                  confidence  the  relevant   Wyeth-Ayerst  records  as  may  be
                  reasonably  necessary to determine and/or verify the amount of
                  Royalty  payments due  hereunder.  Such  examination  shall be
                  conducted during  Wyeth-Ayerst's  normal business hours, after
                  at  least   fifteen   (15)  days  prior   written   notice  to
                  Wyeth-Ayerst   and  shall  take  place  at  the   Wyeth-Ayerst
                  facility(ies)  where such  records are  maintained.  Each such
                  examination  shall be limited to  pertinent  books and records
                  for any year ending not more than thirty-six (36) months prior
                  to the date of request.  Before  permitting  such  independent
                  accounting  firm to have  access to such  books  and  records,
                  Wyeth-Ayerst may require such independent  accounting firm and
                  its   personnel   involved   in   such   audit,   to   sign  a
                  confidentiality  agreement (in form and  substance  reasonably
                  acceptable to Wyeth-Ayerst) as to any of  Wyeth-Ayerst's,  its
                  Affiliates or sublicensees'  confidential information which is
                  to be  provided  to  such  accounting  firm or to  which  such
                  accounting firm will have access,  while  conducting the audit
                  under  this  Section  9.5  (e).  The  Neurocrine   independent
                  accounting  firm will  prepare and provide to both  Neurocrine
                  and Wyeth-Ayerst a written report  disclosing only whether the
                  Royalty  reports  submitted and Royalties paid by Wyeth-Ayerst
                  are correct or incorrect and the specific  details  concerning
                  any  discrepancies.  No other information shall be provided to
                  Neurocrine.  In  the  event  there  was  an  under-payment  by
                  Wyeth-Ayerst hereunder, Wyeth-Ayerst shall promptly (but in no
                  event later than thirty (30) days after Wyeth-Ayerst's receipt
                  of the independent  auditor's report so correctly  concluding)
                  make payment to  Neurocrine  of any  short-fall.  In the event
                  that  there was an  over-payment  by  Wyeth-Ayerst  hereunder,
                  Neurocrine  shall  promptly (but in no event later than thirty
                  (30)  days  after  Neurocrine's  receipt  of  the  independent
                  auditor's   report   so   correctly   concluding)   refund  to
                  Wyeth-Ayerst  the excess  amount.  In the event any payment by
                  Wyeth-Ayerst  shall prove to have been  incorrect by more than
                  seven and one-half  percent (7.5%) to Neurocrine's  detriment,
                  Wyeth-Ayerst  will  pay  the  reasonable  fees  and  costs  of
                  Neurocrine's independent auditor for conducting such audit.

9.5      Third Party Payments.

        (a)       OHSU  Agreement.  The Parties have agreed to share equally the
                  royalty  payments to OHSU required under paragraph 6.02 of the
                  OHSU Agreement (the "Shared  Obligation").  All other payments
                  under  the  OHSU  Agreement  shall  be the  responsibility  of
                  Neurocrine.  Neurocrine  shall be  responsible  for making all
                  payments due under the OHSU License  Agreement and, within ten
                  (10) days of making any payment  required under paragraph 6.02
                  of  the  OHSU   Agreement,   Neurocrine   shall   provide   to
                  Wyeth-Ayerst  documentary  evidence that such payment has been
                  made. Within thirty (30) days after Wyeth-Ayerst receives from
                  Neurocrine such documentary  evidence,  Wyeth-Ayerst shall pay
                  to  Neurocrine an amount equal to [***] of the payments due to
                  the Oregon Health  Sciences  University  pursuant to [***] for
                  Licensed  Patent  Rights (as  defined  in the OHSU  Agreement)
                  included in the Neurocrine Technology licensed to Wyeth-Ayerst
                  hereunder, provided, however, that any credits that may accrue
                  to  Neurocrine  by reason of  payments by  Neurocrine  to OHSU
                  pursuant  to  [***]  will  be  considered  a  credit   against
                  Neurocrine's  portion of Shared  Obligation,  and any  credits
                  that may accrue pursuant to [***] or Wyeth-Ayerst, as the case
                  may be, will be considered a credit  against  Neurocrine's  or
                  Wyeth-Ayerst's,    respectively,   portion   of   the   Shared
                  Obligation.

        (b)       Neurocrine  Technology.  [***] from any Third Party  owning or
                  Controlling  Patent  Rights  which would be infringed by [***]
                  under this  Agreement,  a license  under such  Patent  Rights,
                  which  license  would permit [***] will be solely  responsible
                  for paying [***] of the license fees and royalties that may be
                  payable to any such Third  Party for such  license(s).  In the
                  event [***] fails or in unable to negotiate an agreement  with
                  such Third Party  within [***] may  negotiate  such license on
                  terms reasonably  agreed to by [***] and in the event [***] in
                  obtaining such license on terms agreed to by [***] in its good
                  faith business judgment [***] amounts payable  thereunder.  If
                  [***] is  unable to agree as to  whether  it is  necessary  to
                  obtain such a license from a Third  Party,  the issue shall be
                  referred to [***].

         (c)      Collaboration  Products.  Except  as set  forth in (a) and (b)
                  above,  [***]  determining  whether to  negotiate an agreement
                  with any Third  Party  that owns or  Controls  a Patent  Right
                  claiming the manufacture or use of any Collaboration  Product.
                  [***] from any Third Party owning or Controlling Patent Rights
                  which would be infringed by the  development  and sale of Lead
                  Compounds  and  Collaboration  Products,  a license under such
                  Patent Rights,  and in the event [***] obtains such a license,
                  [***]  shall pay [***] that may be payable to such Third Party
                  for such license(s).

        (d)       Third Party Licenses.  Any rights to Third Party Patent Rights
                  licensed by  Neurocrine or  Wyeth-Ayerst,  as the case may be,
                  under  paragraphs  (b)  and (c)  above,  shall  be  considered
                  Neurocrine    Technology    or    Wyeth-Ayerst     Technology,
                  respectively.  In each case, Wyeth-Ayerst and Neurocrine shall
                  use their Commercially  Reasonable Efforts to ensure that such
                  licenses  provide  for the  right to  sublicense  of the Third
                  Party  Patent  Rights in  connection  with the  license of the
                  Neurocrine   Technology  and   Wyeth-Ayerst   Technology  upon
                  termination of this Agreement  pursuant to Article Twelve. Any
                  sublicenses  of Third Party Patent Rights  pursuant to Article
                  Twelve shall be subject to the assumption by the Party to whom
                  the rights are  sublicensed  of all  payment  and  performance
                  obligations in connection with the exercise of the sublicensed
                  rights by such Party.


                                   ARTICLE TEN
                        CONFIDENTIALITY, PUBLICATION AND
                              PUBLIC ANNOUNCEMENTS

10.1     Confidentiality.  Except to the  extent  expressly  authorized  by this
         Agreement or otherwise  agreed in writing,  the Parties agree that, for
         the term of this  Agreement and for [***],  each Party (the  "Receiving
         Party"),  receiving hereunder any information  designated  hereunder as
         Confidential Information of the other Party or information of the other
         Party marked  "Confidential" (in either case, the "Disclosing  Party"),
         shall  keep such  information  confidential  and shall not  publish  or
         otherwise disclose or use for any purpose other than as provided for in
         this Agreement except, to the extent that it can be established:

        (a)       by the Receiving Party that the  Confidential  Information was
                  already  known to the  Receiving  Party  (other  than under an
                  obligation of  confidentiality),  at the time of disclosure by
                  the Disclosing  Party and such Receiving Party has documentary
                  evidence to that effect;

        (b)       by the Receiving Party that the  Confidential  Information was
                  generally  available  to the public or  otherwise  part of the
                  public  domain at the time of its  disclosure to the Receiving
                  Party;

        (c)       by the  Receiving  Party  that  the  Confidential  Information
                  became generally  available to the public or otherwise part of
                  the public domain after its disclosure or development,  as the
                  case may be, and other than  through  any act or omission of a
                  party in breach of this confidentiality obligation;

        (d)       by the Receiving Party that the  Confidential  Information was
                  disclosed  to that Party,  other than under an  obligation  of
                  confidentiality, by a Third Party who had no obligation to the
                  Disclosing Party not to disclose such information to others;

        (e)       by the Receiving Party that the  Confidential  Information was
                  independently  discovered or developed by the Receiving  Party
                  without the use of the Confidential  Information  belonging to
                  the  other  Party  and the  Receiving  Party  has  documentary
                  evidence to that effect

10.2     Authorized Disclosure.

        (a)       Each Party. Each Party may disclose  Confidential  Information
                  belonging to the other Party to the extent such  disclosure is
                  reasonably necessary to:

                           (i)      file  or   prosecute   patent   applications
                                    claiming   inventions  included  within  the
                                    Collaboration Technology,

                           (ii)     prosecute or defend litigation,

                           (iii)    exercise  rights  hereunder   provided  such
                                    disclosure    is   covered   by   terms   of
                                    confidentiality  similar  to those set forth
                                    herein, and

                           (iv)     comply with applicable governmental laws and
                                    regulations.

                  In the  event a Party  shall  deem it  necessary  to  disclose
                  pursuant to this  Section 10.2 (a),  Confidential  Information
                  belonging to the other Party,  the  Disclosing  Party shall to
                  the extent  possible give  reasonable  advance  notice of such
                  disclosure to the other Party and take reasonable  measures to
                  ensure confidential treatment of such information.

        (b)       Use.  Wyeth-Ayerst  shall  have the  right  to use  Neurocrine
                  Confidential  Information  in  the  conduct  of  the  Research
                  Program and in developing and  commercializing  Lead Compounds
                  and Collaboration Products. Neurocrine shall have the right to
                  use  Wyeth-Ayerst  Confidential  Information in the conduct of
                  the Research Program and, in the event this Agreement shall be
                  terminated in accordance with Sections 12.3, 12.4,  12.5(a) or
                  12.6,  in  the  development  and   commercialization  of  Lead
                  Compounds  and  Collaboration  Products and  Compounds  [***].
                  Neurocrine  shall  also have the right to use that  portion of
                  the Wyeth-Ayerst  Confidential Information that relates [***].
                  Subject to the license granted in Article Three hereof and the
                  terms of this Article Ten,  each Party shall have the right to
                  use the Joint Confidential Information for any purpose.

10.3     SEC Filings.  The Parties will consult with one another on the terms of
         this Agreement to be redacted in SEC filings.

10.4     Publications.  During the term of the Research Program, each Party will
         submit  to the  other  Party  for  review  and  approval  all  proposed
         academic,  scientific and medical publications relating to the Research
         Program,  Lead Compounds,  Collaboration  Products and/or Collaboration
         Technology  for review in  connection  with  preservation  of exclusive
         Patent  Rights  and/or to determine  whether  Confidential  Information
         should be modified or deleted.  The  nonpublishing  Party shall have no
         less than  thirty (30) days to review each  proposed  publication.  The
         review period may be extended for an additional thirty (30) days in the
         event the  nonpublishing  Party can  demonstrate a reasonable  need for
         such  extension  including,  but not  limited to, the  preparation  and
         filing of patent applications.  By mutual agreement, this period may be
         further  extended.  Wyeth-Ayerst  and Neurocrine  will each comply with
         standard   academic   practice   regarding   authorship  of  scientific
         publications  and  recognition of  contribution of other parties in any
         publications    relating   to   Research   Program,   Lead   Compounds,
         Collaboration Products and/or Collaboration Technology.
10.5     Public Announcements.

         (a)      Coordination.   The  Parties   agree  on  the   importance  of
                  coordinating  their  public   announcements   respecting  this
                  Agreement and the subject matter thereof (other than academic,
                  scientific  or medical  publications  that are  subject to the
                  publication   provision  set  forth  above).   Neurocrine  and
                  Wyeth-Ayerst  will,  from time to time,  and at the request of
                  the other Party  discuss and agree on the general  information
                  content relating to this Agreement, the Research Program, Lead
                  Compounds,   Collaboration   Products   and/or   Collaboration
                  Technology which may be publicly disclosed.

         (b)      Announcements. Neither Party will make any public announcement
                  (whether   required  by  law  or  otherwise)   regarding  this
                  Agreement, the Research Program, Lead Compounds, Collaboration
                  Products and/or Collaboration Technology (other than academic,
                  scientific  or medical  publications  which are subject to the
                  publication  provision  set forth  above)  without  giving the
                  other Party the  opportunity  to review and  comment  prior to
                  release.


                                 ARTICLE ELEVEN
                                 INDEMNIFICATION

11.1     Indemnification  by Wyeth-Ayerst.  Wyeth-Ayerst will indemnify,  defend
         and hold harmless Neurocrine, its Affiliates, and each of its and their
         respective   employees,   officers,   directors  and  agents  (each,  a
         "Neurocrine Indemnified Party") from and against any and all liability,
         loss,  damage,   expense  (including  reasonable  attorneys'  fees  and
         expenses) and cost  (collectively,  a "Liability") which the Neurocrine
         Indemnified  Party may be required to pay to one or more Third  Parties
         resulting  from or arising  out of (i) any claims of any nature  (other
         than claims by Third Parties relating to patent  infringement)  arising
         out (y) the  conduct of the  Research  Program or use of  Collaboration
         Technology  of by,  on behalf of or under  authority  of,  Wyeth-Ayerst
         (other  than  by  Neurocrine)  or  (z)  research,   development  and/or
         commercialization of Lead Compounds and/or  Collaboration  Products by,
         on  behalf  of or  under  authority  of,  Wyeth-Ayerst  (other  than by
         Neurocrine) and/or (ii) any Wyeth-Ayerst representation or warranty set
         forth herein being untrue in any material respect when made,  except in
         each case, to the extent caused by the negligence or willful misconduct
         of Neurocrine or any Neurocrine Indemnified Party.  Notwithstanding the
         foregoing,  Wyeth-Ayerst shall have no obligation to defend,  indemnify
         or hold harmless any Neurocrine  Indemnified Party from and against any
         Liability  arising out of or resulting from the infringement of a Third
         Party Patent Right.

11.2     Indemnification  by Neurocrine.  Neurocrine will indemnify,  defend and
         hold harmless Wyeth-Ayerst,  its Affiliates,  and each of its and their
         respective   employees,   officers,   directors  and  agents  (each,  a
         "Wyeth-Ayerst  Indemnified  Party") from and against and all  Liability
         which the Wyeth-Ayerst  Indemnified Party may be required to pay to one
         or more  Third  Parties  arising  out of (i) any  claims of any  nature
         (other than claims by Third  Parties  relating to patent  infringement)
         arising out of the conduct of the Research Program by, on behalf of, or
         under the authority of Neurocrine  (other than by Wyeth-Ayerst)  and/or
         (ii) any Neurocrine  representation or warranty set forth herein having
         been untrue in any material respect when made,  except in each case, to
         the  extent  caused  by  the   negligence  or  willful   misconduct  of
         Wyeth-Ayerst or any Wyeth-Ayerst Indemnified Party. Notwithstanding the
         foregoing,  Neurocrine shall have no obligation to defend, indemnify or
         hold harmless any Wyeth-Ayerst  Indemnified  Party from and against any
         Liability  arising out of or resulting from the infringement of a Third
         Party Patent Right.

11.3     Procedure.  Each  Party  will  notify the other in the event it becomes
         aware of a claim for which indemnification may be sought hereunder.  In
         case any proceeding (including any governmental investigation) shall be
         instituted  involving  any Party in respect of which  indemnity  may be
         sought  pursuant to this Article Eleven,  such Party (the  "Indemnified
         Party")  shall  promptly  notify  the other  Party  (the  "Indemnifying
         Party") in writing and the  Indemnifying  Party and  Indemnified  Party
         shall meet to discuss how to respond to any claims that are the subject
         matter of such proceeding.  The Indemnifying Party, upon request of the
         Indemnified Party, shall retain counsel reasonably  satisfactory to the
         Indemnified  Party to represent the Indemnified Party and shall pay the
         fees and expenses of such counsel  related to such  proceeding.  In any
         such proceeding,  the Indemnified  Party shall have the right to retain
         its own counsel,  but the fees and expenses of such counsel shall be at
         the expense of the Indemnified Party unless (i) the Indemnifying  Party
         and the  Indemnified  Party shall have mutually agreed to the retention
         of such  counsel  or (ii) the  named  parties  to any  such  proceeding
         (including any impleaded  parties) include both the Indemnifying  Party
         and the  Indemnified  Party and  representation  of both parties by the
         same  counsel  would  be  inappropriate  due  to  actual  or  potential
         differing  interests  between them. All such fees and expenses shall be
         reimbursed as they are incurred.  The  Indemnifying  Party shall not be
         liable  for any  settlement  of any  proceeding  effected  without  its
         written  consent,  but if  settled  with such  consent or if there be a
         final  judgment for the  plaintiff,  the  Indemnifying  Party agrees to
         indemnify the Indemnified  Party from and against any loss or liability
         by reason of such settlement or judgment.  The Indemnifying Party shall
         not, without the written consent of the Indemnified  Party,  effect any
         settlement of any pending or threatened  proceeding in respect of which
         the Indemnified Party is, or arising out of the same set of facts could
         have been, a party and  indemnity  could have been sought  hereunder by
         the Indemnified Party, unless such settlement includes an unconditional
         release of the Indemnified  Party from all liability on claims that are
         the subject matter of such proceeding.

11.4     Insurance. Each Party further agrees to use its Commercially Reasonable
         Efforts to obtain  and  maintain,  during  the term of this  Agreement,
         Commercial  General Liability  Insurance,  including Products Liability
         Insurance,  with reputable and financially secure insurance carriers to
         cover its  indemnification  obligations under Sections 11.1 or 11.2, as
         applicable,  or self-insurance,  with limits of not less than [***] per
         occurrence and in the aggregate.


                                 ARTICLE TWELVE
                              TERM AND TERMINATION

12.1     Government Approvals.

         (a)      Government  Approvals.  Each of  Neurocrine  and  Wyeth-Ayerst
                  shall use its good faith  efforts to eliminate  any concern on
                  the part of any court or  government  authority  regarding the
                  legality of the proposed transaction,  including,  if required
                  by federal or state antitrust authorities, promptly taking all
                  steps to secure  government  antitrust  clearance,  including,
                  without  limitation,   cooperating  in  good  faith  with  any
                  government  investigation  including the prompt  production of
                  documents  and  information  demanded by a second  request for
                  documents and of witnesses if requested.

         (b)      Co-operation.  Neurocrine and Wyeth-Ayerst  will cooperate and
                  use  respectively  all  reasonable  efforts  to make all other
                  registrations,  filings and applications,  to give all notices
                  and to obtain as soon as practicable all governmental or other
                  consents,   transfers,   approvals,   orders,   qualifications
                  authorizations,  permits and  waivers,  if any,  and to do all
                  other things  necessary or desirable for the  consummation  of
                  the transactions as contemplated  hereby.  Neither Party shall
                  be  required,   however,  to  divest  products  or  assets  or
                  materially  change its  business if doing so is a condition of
                  the transactions contemplated by this Agreement.

12.2     Term.  Unless earlier  terminated by mutual agreement of the Parties or
         pursuant to the provisions of this Article Twelve,  this Agreement will
         continue  in  full  force  and  effect  on  a  country-by  country  and
         Collaboration   Product  by  Collaboration   Product  basis  until  the
         obligation  to  pay  Royalties   with  respect  to  the  sale  of  such
         Collaboration  Product in such  country  expires as provided in Section
         9.3 hereof.

12.3     Early  Termination  for [***].  In the event that at any time after the
         [***]  anniversary of the Effective Date, the Steering  Committee shall
         determine that [***] as set forth in Exhibit B Parts 1(a),  1(b),  2(a)
         and 2(b),  has been  demonstrated  for [***] (or, if this Agreement has
         already been terminated with respect to [***] pursuant to Section 12.4,
         the  [***]  subject  to this  Agreement),  Wyeth-Ayerst  may  elect  to
         terminate  this  Agreement  upon [***] months prior  written  notice to
         Neurocrine.  Upon such  termination,  Wyeth-Ayerst will have no further
         funding  obligation  for  the  Research  Program.  In  the  event  this
         Agreement  shall be  terminated  pursuant  to this  Section  12.3,  all
         licenses granted by Neurocrine to Wyeth-Ayerst hereunder will revert to
         Neurocrine and:

                  (i)      Wyeth-Ayerst will disclose to Neurocrine all material
                           Research Program  research and  pre-clinical  data on
                           Hits  generated  prior  to the  date  of  termination
                           provided  such  data  are  reasonably   available  to
                           Wyeth-Ayerst  and Neurocrine  shall have the right to
                           use such data,  at its own risk and  expense,  in its
                           development  of  Compounds  (other than  Wyeth-Ayerst
                           Compounds) which [***]

                   (ii)    Wyeth-Ayerst  will grant to  Neurocrine  a perpetual,
                           irrevocable,  exclusive,  royalty-free,   fully-paid,
                           worldwide  license under the Wyeth-Ayerst  Technology
                           and  Wyeth-Ayerst's  interest in the Joint Technology
                           to make, have made, use,  import,  market,  offer for
                           sale and sell in the Field of Use,  Compounds  (other
                           than Wyeth-Ayerst Compounds) which [***]

                  (iii)    Wyeth-Ayerst   shall   remain  free  to  develop  and
                           commercialize  any Wyeth-Ayerst  Compound,  provided,
                           however,  that such Compound is not developed for any
                           indication in [***] and the continued identification,
                           development  and  commercialization  of such Compound
                           does not utilize Neurocrine Technology.

12.4     Termination of Collaboration Product Development and Commercialization.
         Subject to  satisfaction of  Wyeth-Ayerst's  minimum  Research  Program
         Funding  commitment (i.e.,  [***] of Research Program Funding),  in the
         event that  Wyeth-Ayerst  shall  elect at any time to  discontinue  all
         activities  relating to the  development and  commercialization  of all
         Collaboration Products which [***] or shall elect to discontinue use of
         Commercially    Reasonable    Efforts    in   the    development    and
         commercialization   of   all   Collaboration   Products   which   [***]
         Wyeth-Ayerst  shall provide written notice to Neurocrine  setting forth
         Wyeth-Ayerst's  election to terminate  this  Agreement  with respect to
         [***] and upon Neurocrine's  receipt of such notice this Agreement with
         respect to [***], will terminate.  In the event this Agreement shall be
         terminated  with respect to a Neurocrine  Transporter  pursuant to this
         Section 12.4:

                  (i)      Wyeth-Ayerst will disclose to Neurocrine all material
                           Research Program research,  pre-clinical and clinical
                           data  generated  prior to the date of  termination on
                           Hits,  Lead  Compounds  and  Collaboration   Products
                           relating to the terminated Neurocrine Transporter(s),
                           provided  such  data  are  reasonably   available  to
                           Wyeth-Ayerst  and Neurocrine  shall have the right to
                           use such data,  at its own risk and  expense,  in its
                           development of Compounds [***] which [***]

                  (ii)     Wyeth-Ayerst  will assign  (or,  if the filing  [***]
                           grant a right of cross  reference) to Neurocrine  all
                           Regulatory  Filings relating to Compounds  designated
                           as Lead Compounds and/or Collaboration Products prior
                           to the date of termination  of this Agreement  (other
                           than Lead  Compounds  and/or  Collaboration  Products
                           which are [***] in so far as such Regulatory  Filings
                           relate to [***];

                  (iii)    Wyeth-Ayerst  will grant to  Neurocrine  a perpetual,
                           irrevocable,  exclusive,  royalty-free,   fully-paid,
                           worldwide license under the [***] to make, have made,
                           use,  sell and import in the Field of Use,  Compounds
                           including Compounds  designated as Lead Compounds and
                           Collaboration   Products   prior   to  the   date  of
                           termination of this  Agreement  (but excluding  [***]
                           only [***] in which [***]

                  (iv)     Wyeth-Ayerst will enter into good faith  negotiations
                           with Neurocrine  regarding the grant to Neurocrine of
                           the  licenses as set forth in (A), (B) and (C) below,
                           to  allow  Neurocrine  to  continue  to  develop  and
                           commercialize,  [***] designated as Lead Compounds or
                           Collaboration   Products   prior   to  the   date  of
                           termination of this Agreement:

                            (A)      an exclusive,  worldwide  license under the
                                     [***]  to make,  have  made,  use,  import,
                                     offer for sale and sell in the Field of Use
                                     [***] which are [***],  such  license to be
                                     on   commercially   reasonable   terms  and
                                     conditions  mutually  agreed by the Parties
                                     including, without limitation, provision of
                                     payments  intended to reflect both Parties'
                                     investment   and    opportunity   in   such
                                     Compounds  and  royalties  on net  sales of
                                     such   [***]  the   Royalties   payable  by
                                     Wyeth-Ayerst  to  Neurocrine  hereunder and
                                     other    terms   and    conditions    which
                                     Wyeth-Ayerst    believes   are   reasonable
                                     necessary    or    desirable   to   protect
                                     Wyeth-Ayerst's  research,  development  and
                                     commercialization activities for [***];

                            (B)      an exclusive,  worldwide  license under the
                                     [***]  to make,  have  made,  use,  import,
                                     offer for sale and sell in the Field of Use
                                     only [***] in which [***], such licenses to
                                     be on  commercially  reasonable  terms  and
                                     conditions  mutually  agreed by the Parties
                                     including, without limitation, provision of
                                     payments  intended to reflect both Parties'
                                     investment   and    opportunity   in   such
                                     Compounds  and  royalties  on net  sales of
                                     such   [***]  the   Royalties   payable  by
                                     Wyeth-Ayerst  to  Neurocrine  hereunder and
                                     other    terms   and    conditions    which
                                     Wyeth-Ayerst    believes   are   reasonable
                                     necessary    or    desirable   to   protect
                                     Wyeth-Ayerst's  research,  development  and
                                     commercialization activities for [***];

                            (C)      an exclusive,  worldwide  license under the
                                     [***]  to make,  have  made,  use,  import,
                                     offer for sale and sell in the Field of Use
                                     only [***] in which [***], such licenses to
                                     be on  commercially  reasonable  terms  and
                                     conditions  mutually  agreed by the Parties
                                     including, without limitation, provision of
                                     payments  intended to reflect both Parties'
                                     investment   and    opportunity   in   such
                                     Compounds  and  royalties  on net  sales of
                                     such    [***]    Royalties    payable    by
                                     Wyeth-Ayerst  to  Neurocrine  hereunder and
                                     other    terms   and    conditions    which
                                     Wyeth-Ayerst    believes   are   reasonable
                                     necessary    or    desirable   to   protect
                                     Wyeth-Ayerst's  research,  development  and
                                     commercialization activities [***]

                           (D)      upon the grant of the  licenses set forth in
                                    (A), (B) and/or (C) above, Wyeth-Ayerst will
                                    assign  (or,  if the  filing  [***]  grant a
                                    right of cross  reference) to Neurocrine all
                                    Regulatory  Filings  on  [***]  that are the
                                    subject  of the  license  in so far as  such
                                    Regulatory  Filings relate [***] which [***]
                                    and

                   (v)     Wyeth-Ayerst  shall  remain  free to  develop  and/or
                           sublicense  any  [***]  to Third  Parties,  provided,
                           however, in no event will Wyeth-Ayerst  commercialize
                           or sublicense  Third Parties to  commercialize  [***]
                           designated   as  Lead   Compounds  or   Collaboration
                           Products  prior  to the date of  termination  of this
                           Agreement (a) for [***] and (b) if the identification
                           or continued  development  and  commercialization  of
                           such Compound utilizes Neurocrine Technology.

         Notwithstanding the foregoing, Wyeth-Ayerst shall have no obligation to
         negotiate or grant any of the  licenses set forth in (iv) (A),  (B), or
         (C) above with respect to [***].

12.5     Default.

         (a)      Wyeth-Ayerst.  Upon the  Default  by  Wyeth-Ayerst  under this
                  Agreement,  Neurocrine may notify Wyeth-Ayerst of such Default
                  and require that  Wyeth-Ayerst cure such Default within [***],
                  provided,  however, that if such Default is not susceptible of
                  cure   within   [***]   period  and   Wyeth-Ayerst   uses  its
                  Commercially  Reasonable  Efforts to cure such  default,  such
                  [***]  period  shall  be  extended  to  [***].  In  the  event
                  Wyeth-Ayerst  shall not have  cured the  Default at the end of
                  the period specified in the preceding sentence, Neurocrine may
                  upon written notice to  Wyeth-Ayerst  terminate this Agreement
                  and upon such termination:

                           (i)      all licenses granted by Neurocrine to Wyeth-
                                    Ayerst herein will revert to Neurocrine:

                           (ii)     Wyeth-Ayerst   will   satisfy   its  minimum
                                    Research Funding commitment  hereunder [***]
                                    to the extent not previously satisfied;

                           (iii)    Wyeth-Ayerst will disclose to Neurocrine all
                                    material    Research    Program    research,
                                    pre-clinical and clinical data on Hits, Lead
                                    Compounds   and    Collaboration    Products
                                    generated  prior to the date of  termination
                                    of this  Agreement,  provided  such data are
                                    reasonably  available  to  Wyeth-Ayerst  and
                                    Neurocrine  thereafter  shall have the right
                                    to use  such  data,  at  its  own  risk  and
                                    expense,  to develop  Compounds  [***] which
                                    [***];

                           (iv)     Wyeth-Ayerst  will assign (or, if the filing
                                    [***] grant a right of cross  reference)  to
                                    Neurocrine all Regulatory  Filings  relating
                                    to Compounds  designated  as Lead  Compounds
                                    and/or  Collaboration  Products prior to the
                                    date of termination of the Agreement  (other
                                    than  Lead  Compounds  and/or  Collaboration
                                    Products  that  are  [***] in so far as such
                                    Regulatory  Filings  relate  [***]  in which
                                    [***];

                           (v)      Wyeth-Ayerst  will  grant  to  Neurocrine  a
                                    perpetual,      irrevocable,      exclusive,
                                    royalty-free,  fully-paid, worldwide license
                                    under [***] to make, have made, use, import,
                                    market, offer for sale and sell in the Field
                                    of  Use,   Compounds   including   Compounds
                                    designated   as   Lead   Compounds    and/or
                                    Collaboration  Products prior to the date of
                                    termination  of this  Agreement  [***]  only
                                    [***] in which [***];

                            (vi)     Wyeth-Ayerst  will grant to  Neurocrine  an
                                     exclusive, worldwide license under [***] to
                                     make, have made, use, import, market, offer
                                     for sale and sell in the  Field of Use only
                                     [***]  in  which   [***]  which  have  been
                                     designated   as   Lead   Compounds   and/or
                                     Collaboration Products prior to the date of
                                     termination of this Agreement, such license
                                     to be on commercially  reasonable terms and
                                     conditions  to be  mutually  agreed  by the
                                     Parties  including  provision  of  payments
                                     intended   to   reflect    both    Parties'
                                     investment   and    opportunity   in   such
                                     Compounds  and  royalties  on net  sales of
                                     [***] Royalties  payable by Wyeth-Ayerst to
                                     Neurocrine  hereunder  provided,   however,
                                     that Wyeth-Ayerst  shall have no obligation
                                     to  negotiate  or grant  any  license  with
                                     respect to any [***]

                           (vii)    upon the grant of the  licenses set forth in
                                    (vi) above, Wyeth-Ayerst will assign (or, if
                                    the filing is not [***] in which [***] grant
                                    a right of cross  reference)  to  Neurocrine
                                    all Regulatory  Filings on the  Wyeth-Ayerst
                                    Compounds   that  are  the  subject  of  the
                                    license in so far as such Regulatory Filings
                                    relates [***] in which [***]; and

                           (viii)   Wyeth-Ayerst  shall  remain  free to develop
                                    and/or  sublicense [***] provided,  however,
                                    in no event will Wyeth-Ayerst  commercialize
                                    or sublicense Third Parties to commercialize
                                    any [***]  designated  as Lead  Compounds or
                                    Collaboration  Products prior to the date of
                                    termination  of this Agreement (a) for [***]
                                    in    which    [***]    and   (b)   if   the
                                    identification,  continued  development  and
                                    commercialization  of such Compound utilizes
                                    Neurocrine Technology.

         (b)      Neurocrine.   Upon  the  Default  by  Neurocrine   under  this
                  Agreement,  Wyeth-Ayerst may notify Neurocrine of such Default
                  and require that  Neurocrine  cure such Default  within [***],
                  provided,  however, that if such Default is not susceptible of
                  cure  within  such  [***]  period  and  Neurocrine   uses  its
                  Commercially  Reasonable  Efforts to cure such  default,  such
                  [***]  period  shall  be  extended  to  [***].  In  the  event
                  Neurocrine  shall not have cured the Default within the period
                  specified in the  preceding  sentence,  Wyeth-Ayerst  may upon
                  written notice to Neurocrine elect to terminate this Agreement
                  and upon such termination:

                           (i)      Neurocrine  will  grant  to  Wyeth-Ayerst  a
                                    perpetual,    irrevocable,    non-exclusive,
                                    royalty-free,  fully paid, worldwide license
                                    under the Neurocrine  Transporter Technology
                                    to make,  have made,  use,  import,  market,
                                    offer for sale and sell in the Field of Use,
                                    Compounds (other than Neurocrine  Compounds)
                                    which [***]

                           (ii)     Neurocrine  will  grant  to  Wyeth-Ayerst  a
                                    perpetual,      irrevocable,      exclusive,
                                    royalty-free,  fully paid, worldwide license
                                    under   the   Neurocrine    Technology   and
                                    Neurocrine's    interest    in   the   Joint
                                    Technology to make, have made, use,  import,
                                    market, offer for sale and sell in the Field
                                    of Use,  Compounds  (other  than  Neurocrine
                                    Compounds), only [***] in which [***]

                           (iii)    Neurocrine  will  grant to  Wyeth-Ayerst  an
                                    exclusive,  royalty-free,  worldwide license
                                    under   the   Neurocrine    Technology   and
                                    Neurocrine's    interest    in   the   Joint
                                    Technology to develop, make, have made, use,
                                    import,  market,  offer for sale and sell in
                                    the Field of Use, Neurocrine Compounds which
                                    have  been   designated  as  Lead  Compounds
                                    and/or  Collaboration  Products prior to the
                                    date of  termination  of this Agreement only
                                    [***].

12.6     Bankruptcy. Each party may, in addition to any other remedies available
         to it by law or in  equity,  exercise  the  rights  set forth  below by
         written notice to the other Party (the "Insolvent Party"), in the event
         the Insolvent Party shall have become  insolvent or bankrupt,  or shall
         have made an  assignment  for the  benefit of its  creditors,  or there
         shall have been appointed a trustee or receiver of the Insolvent  Party
         or for  all or a  substantial  part  of its  property,  or any  case or
         proceeding  shall  have  been  commenced  or other  action  taken by or
         against the Insolvent  Party in  bankruptcy or seeking  reorganization,
         liquidation,   dissolution,  winding-up  arrangement,   composition  or
         readjustment  of its debts or any other  relief  under any  bankruptcy,
         insolvency,   reorganization  or  other  similar  act  or  law  of  any
         jurisdiction  now or  hereafter  in  effect,  or there  shall have been
         issued a warrant of attachment, execution, distraint or similar process
         against any  substantial  part of the property of the Insolvent  Party,
         and  any  such  event  shall  have   continued   for  sixty  (60)  days
         undismissed, unbonded and undischarged. All rights and licenses granted
         under or pursuant to this Agreement by Neurocrine and Wyeth-Ayerst are,
         and shall otherwise be deemed to be, for purposes of Section 365 (n) of
         the U.S. Bankruptcy Code, licenses of rights to "intellectual property"
         as defined under Section 101 of the U.S.  Bankruptcy  Code. The Parties
         agree  that  the  Parties  as  licensees  of  such  rights  under  this
         Agreement,  shall retain and may fully exercise all of their rights and
         elections  under the U.S.  Bankruptcy  Code. The Parties  further agree
         that, in the event of the commencement of a bankruptcy proceeding by or
         against  either Party under the U.S.  Bankruptcy  Code, the other Party
         shall be entitled to a complete duplicate of (or complete access to, as
         appropriate) any such intellectual property and all embodiments of such
         intellectual   property,   and  same,  if  not  already  in  the  their
         possession,  shall  be  promptly  delivered  to them  (i) upon any such
         commencement  of a  bankruptcy  proceeding  upon  its  written  request
         therefor,  unless  the  Party  subject  to such  proceeding  elects  to
         continue to perform all of their  obligations  under this  Agreement or
         (ii) if not  delivered  under (i)  above,  upon the  rejection  of this
         Agreement by or on behalf of the Party subject to such  proceeding upon
         written request therefor by the other Party.

         (a)      Neurocrine. In the event Neurocrine shall be an Insolvent 
                  Party, Wyeth-Ayerst:

                  (i)      may terminate the Research Program; and/or

                  (ii)     keep this  Agreement  in full  force and  effect  and
                           retain  all  licenses   granted  by   Neurocrine   to
                           Wyeth-Ayerst  herein to make, have made, use, import,
                           market,  offer for sale and sell Lead  Compounds  and
                           Collaboration  Products in the Field of Use,  subject
                           to the payment to  Neurocrine of the License Fees and
                           Royalties set forth above.

         (b)      Wyeth-Ayerst.  In the event Wyeth-Ayerst shall be an Insolvent
                  Party,  Neurocrine may, to the extent  permitted by applicable
                  law,  terminate  this  Agreement  and all licenses  granted by
                  Neurocrine  to  Wyeth-Ayerst  herein will revert to Neurocrine
                  and:

                  (i)      Wyeth-Ayerst will disclose to Neurocrine all material
                           Research Program research,  pre-clinical and clinical
                           data  on  Hits,  Lead  Compounds  and   Collaboration
                           Products  generated  prior to the date of termination
                           provided  such  data  are  reasonably   available  to
                           Wyeth-Ayerst and Neurocrine thereafter shall have the
                           right to use such data,  at its own risk and expense,
                           to develop Compounds [***] which [***]

                  (ii)     Wyeth-Ayerst  will  assign  (or, if the filing is not
                           [***]  in  which   [***]   grant  a  right  of  cross
                           reference)  to  Neurocrine  all  Regulatory   Filings
                           relating  to  Lead  Compounds  and/or   Collaboration
                           Products   (other   than   Lead   Compounds    and/or
                           Collaboration  Products  [***])  in so  far  as  such
                           Regulatory Filings relate [***] in which [***];

                  (iii)    Wyeth-Ayerst  will grant to  Neurocrine  a perpetual,
                           irrevocable,  exclusive,  royalty-free,   fully-paid,
                           worldwide  license  [***] to make,  have  made,  use,
                           import,  market, offer for sale and sell in the Field
                           of Use, Compounds ([***]) which [***];

                  (iv)     Wyeth-Ayerst  will grant to Neurocrine,  a perpetual,
                           irrevocable,  exclusive,  royalty  free,  fully-paid,
                           worldwide  license  [***] to make,  have  made,  use,
                           import,  market, offer for sale and sell in the Field
                           of  Use,  Neurocrine  Compounds  designated  as  Lead
                           Compounds and/or Collaboration  Products prior to the
                           date of  termination  of this  Agreement for [***] in
                           which [***];

                  (v)      Wyeth-Ayerst  will grant to  Neurocrine an exclusive,
                           worldwide  license  under  [***] to make,  have made,
                           use, import,  market,  offer for sale and sell in the
                           Field of Use,  [***]  which have been  designated  as
                           Lead Compounds and/or Collaboration Products prior to
                           the date of  termination  of this Agreement for [***]
                           in which [***],  such  license to be on  commercially
                           reasonable  terms and conditions  mutually  agreed by
                           the Parties including  provision of payments intended
                           to reflect both Parties'  investment and  opportunity
                           in such  Compounds and royalties on net sales of such
                           [***]   Royalties   and  License   Fees   payable  by
                           Wyeth-Ayerst  to  Neurocrine  hereunder  and upon the
                           grant of such  license,  Wyeth-Ayerst  will assign to
                           Neurocrine all Regulatory Filings on [***] which have
                           been    designated   as   Lead    Compounds    and/or
                           Collaboration   Products   prior   to  the   date  of
                           termination of this Agreement.

12.7     Acquisition.  Upon the  Acquisition  of Neurocrine by a Third Party (a)
         such that Neurocrine  [***], (b) such that Neurocrine [***], or (c) who
         is [***],  Wyeth-Ayerst  shall  have the right at any time on or before
         [***] following such the completion of such Acquisition to elect one or
         more of the following:

                  (a)      terminate the Research Program;

                  (b)      terminate this Agreement; or

                  (c)      keep this  Agreement  in full  force and  effect  and
                           retain  all  licenses   granted  by   Neurocrine   to
                           Wyeth-Ayerst herein to make, have made, use, sell and
                           import Lead Compounds and Collaboration  Products, in
                           the  Field  of  Use,   subject  to  the   payment  to
                           Neurocrine  of the  License  Fees and  Royalties  set
                           forth above.

12.8     Liabilities.  Termination  of this  Agreement  shall not release either
         Party from any obligation or liability  which shall have accrued at the
         time of termination,  or preclude either Party from pursuing all rights
         at law and in equity with respect to any Default under this  Agreement.
         Notwithstanding  the  foregoing,  neither  Party  will  be  liable  for
         punitive,  exemplary  or  consequential  damages  incurred by the other
         Party arising out of any Default under this Agreement.

12.9     Disclaimer.  WITH  RESPECT  TO ANY DATA,  INFORMATION  OR  INTELLECTUAL
         PROPERTY THAT EITHER PARTY  BECOMES  OBLIGATED TO TRANSFER TO THE OTHER
         UNDER  THIS   ARTICLE   TWELVE,   THE   TRANSFERING   PARTY   MAKES  NO
         REPRESENTATIONS  AND EXPRESSLY DISCLAIMS AND MAKES NO WARRANTIES OF ANY
         KIND,  WRITTEN  OR  ORAL,  EXPRESS  OR  IMPLIED,   INCLUDING,   WITHOUT
         LIMITATION  ANY  WARRANTIES  OF   MERCHANTABILITY   OR  FITNESS  FOR  A
         PARTICULAR PURPOSE, OR THAT ANY SUCH INFORMATION,  DATA OR INTELLECTUAL
         PROPERTY IS ACCURATE OR COMPLETE OR CAN BE USED BY THE RECEIVING  PARTY
         WITHOUT INFRINGING THE INTELLECTUAL PROPERTY RIGHTS OF ANY THIRD PARTY.


                                ARTICLE THIRTEEN
                              INTELLECTUAL PROPERTY

13.1     Inventions. Each Party shall own Patent Rights claiming inventions made
         by  its  employees  or  agents  in  the  performance  of  such  Party's
         obligations under this Agreement (respectively, "Neurocrine Inventions"
         and  "Wyeth-Ayerst  Inventions")  and both  Parties  shall  jointly own
         inventions  made  jointly by employees or agents of both Parties in the
         performance  of  their  obligations   hereunder  ("Joint  Inventions").
         Inventorship  shall be determined in accordance with United States laws
         of inventorship.

13.2     Patent Prosecution.

         (a)      Wyeth-Ayerst    Inventions   and    Collaboration    Products.
                  Wyeth-Ayerst,   at  its   expense,   shall  use   Commercially
                  Reasonable Efforts to prepare,  file, prosecute,  and maintain
                  worldwide   (i)  Patent   Rights   relating  to   Wyeth-Ayerst
                  Inventions  and (ii) Patent  Rights  claiming  Lead  Compounds
                  and/or   Collaboration   Products   exclusively   licensed  to
                  Wyeth-Ayerst hereunder.

         (b)      OHSU Licensed  Patent  Rights.  Consistent  with the terms and
                  conditions of the OHSU  Agreement,  OHSU shall be  responsible
                  for preparation, filing, prosecution and maintenance of Patent
                  Rights  relating to the Licensed  Patent Rights (as defined in
                  the OSHU Agreement) included in the Collaboration  Technology.
                  Wyeth-Ayerst  and  Neurocrine  will [***] after the  Effective
                  Date in connection with the preparation,  filing,  prosecution
                  and maintenance of such Patent Rights.  Wyeth-Ayerst shall pay
                  to Neurocrine  its share of such  expenses  within thirty (30)
                  days  after  Wyeth-Ayerst's  receipt  from  Neurocrine  of  an
                  invoice  therefor,  which  invoice  shall  be  accompanied  by
                  supporting  documentation  showing,  in reasonable detail, the
                  expenses so incurred.

         (c)      Neurocrine   Inventions.    Neurocrine,    [***],   will   use
                  Commercially  Reasonable Efforts to prepare,  file, prosecute,
                  and maintain  worldwide  Patent Rights  relating to Neurocrine
                  Inventions.

         (d)      Joint Inventions.  Wyeth-Ayerst, [***], shall use Commercially
                  Reasonable Efforts to prepare,  file, prosecute,  and maintain
                  worldwide Patent Rights relating to Joint Inventions.

13.3     Enforcement of Patent Rights.

         (a)      Wyeth-Ayerst  Inventions.  Wyeth-Ayerst  shall  have  the sole
                  right but not the  obligation,  in its own name and at its own
                  expense,  to enforce  Patent Rights  relating to  Wyeth-Ayerst
                  Inventions or Wyeth-Ayerst  Technology against any Third Party
                  suspected of infringing a claim of such a Patent Right.

         (b)      Neurocrine Inventions and Joint Inventions. Wyeth-Ayerst shall
                  have the first right, but not the obligation, in its own name,
                  to enforce Patent Rights relating to Neurocrine Inventions and
                  Joint  Inventions,   against  any  Third  Party  suspected  of
                  infringing  a  claim  of such a  Patent  Right.  In the  event
                  Wyeth-Ayerst  shall  not elect to  enforce  any  Patent  Right
                  relating  to  a  Neurocrine   Invention  or  Joint  Invention,
                  Neurocrine  shall have the right to do so. The Party  electing
                  to enforce such Patent  Rights (the  "Enforcing  Party") shall
                  have   exclusive   control   over  the  conduct  of  any  such
                  proceedings,  including the right to settle or compromise such
                  proceedings consistent with Wyeth-Ayerst's licenses hereunder,
                  provided,  however, that the Enforcing Party may not settle or
                  compromise  any such action in a manner which  diminishes  the
                  Patent Rights  relating to any Neurocrine  Inventions  without
                  Neurocrine's  consent or Joint Inventions  without the consent
                  of both Parties or which would impose any financial obligation
                  on the other Party  without such other  Party's  consent.  The
                  expenses of any  proceeding  the  Enforcing  Party  initiates,
                  including  lawyers'  fees  and  costs,  shall  be borne by the
                  Enforcing Party, provided,  however, that the other Party (the
                  "Non-enforcing  Party")  may  elect  to pay  [***] of all such
                  expenses.  The  Non-enforcing  Party will cooperate fully with
                  the  Enforcing  Party  in  such  action  upon  request  by the
                  Enforcing Party. In the event the Non-enforcing  Party has not
                  elected  [***],  any award or recovery  paid to the  Enforcing
                  Party by a Third Party as a result of such patent infringement
                  proceedings  (whether by way of settlement or otherwise) shall
                  first be applied toward reimbursement of legal fees, costs and
                  expenses  incurred  by  the  Enforcing  Party,  and  from  the
                  remainder,  if any,  Wyeth-Ayerst  in the  event  Wyeth-Ayerst
                  shall be the  Enforcing  Party  shall  pay to  Neurocrine  (or
                  Neurocrine  shall retain in the event  Neurocrine shall be the
                  Enforcing  Party) an amount  equal to the  applicable  Royalty
                  rate set forth in Article Nine as applied to the  remainder as
                  though such  remainder  were added to Net Sales in the year in
                  which the  recovery  is made.  In the event the  Non-enforcing
                  Party  [***],  such award or  recovery  paid to the  Enforcing
                  Party shall  first be applied  toward  reimbursement  of legal
                  fees,   costs  and  expenses   incurred  by  the  Parties  (in
                  proportion to expenses incurred),  and the remainder,  if any,
                  shall be divided equally between the Parties.

         (c)      OHSU Licensed  Patent Rights.  Wyeth-Ayerst,  as  Neurocrine's
                  exclusive sublicensee of certain Patent Rights included in the
                  OHSU   Licensed   Patent   Rights  (as  defined  in  the  OHSU
                  Agreement),  shall have with respect to patent  enforcement of
                  Patent Rights exclusively licensed to Wyeth-Ayerst  hereunder,
                  the rights of an exclusive sublicensee under Article Eleven of
                  the OHSU Agreement.

         (d)      Neurocrine  Technology.  Neurocrine  shall have the sole right
                  but  not  the  obligation,  in its  own  name  and at its  own
                  expense,  to enforce  Patent  Rights  relating  to  Neurocrine
                  Technology (other than Neurocrine Inventions and OHSU Licensed
                  Patent Rights (as defined in the OHSU Agreement))  against any
                  Third Party  suspected of  infringing a claim of such a Patent
                  Right.

13.4     Infringement Defense.

         (a)      Wyeth-Ayerst.  Wyeth-Ayerst  shall have the right, but not the
                  obligation,  to defend and  control  any suit  against  any of
                  Wyeth-Ayerst,   Wyeth-Ayerst's   Affiliates  or  sublicensees,
                  alleging  infringement  of any  patent  or other  intellectual
                  property   right  of  a  Third   Party   arising  out  of  the
                  manufacture,  use,  sale,  offer to sell or  importation  of a
                  Collaboration   Product   by   Wyeth-Ayerst,    Wyeth-Ayerst's
                  Affiliates or sublicensees.  Wyeth-Ayerst shall be responsible
                  for the costs and expenses, including lawyer's fees and costs,
                  associated   with  any  suit  or  action,   Wyeth-Ayerst   and
                  Neurocrine  will consult with one another and cooperate in the
                  defense of any such action. If Wyeth-Ayerst finds it necessary
                  or desirable to join Neurocrine as a party to any such action,
                  Neurocrine  will  execute all papers and perform  such acts as
                  shall be reasonably required,  at Wyeth-Ayerst expense. In the
                  event the patent  claim of any Third  Party is held in a final
                  and  unappealable  order of a court to be valid and infringed,
                  or  if   Wyeth-Ayerst   enters  into  a  settlement   of  such
                  proceedings,  Wyeth-Ayerst  shall  pay the full  amount of any
                  damages  and/or  settlement  amounts due to such Third  Party,
                  provided, however, [***].

         (b)      OHSU Licensed  Patent Rights.  Wyeth-Ayerst,  as  Neurocrine's
                  exclusive sublicensee of certain Patent Rights included in the
                  OHSU   Licensed   Patent   Rights  (as  defined  in  the  OHSU
                  Agreement),  shall have with respect to  infringement  defense
                  relating  to  Licensed  Patent  Rights (as defined in the OHSU
                  Agreement) exclusively licensed to Wyeth-Ayerst hereunder, the
                  rights of an exclusive sublicensee under Article Eleven of the
                  OHSU Agreement.

13.5     Cooperation  Between  the  Parties.  The  Parties  recognize  that  the
         designation of a Compound as a Lead Compound or  Collaboration  Product
         may impact the designation of the Party  responsible for such invention
         under  this  Article  Thirteen.  The  Parties  anticipate  that  patent
         applications  may be filed on  Compounds  prior to  designation  of the
         Compound  as Lead  Compound  or  Collaboration  Product,  and  agree to
         co-operate in deciding how to allocate responsibilities and expenses in
         the event designation of a Compound as a Lead Compound or Collaboration
         Product  impacts  responsibilities  under  this  Article  Thirteen.  In
         addition,  the  Parties  agree  to  cooperate  with  each  other in the
         preparation, filing, prosecuting,  maintenance, defense and enforcement
         of  Patent  Rights  included  in  Collaboration   Technology   licensed
         hereunder. In any action taken in the prosecution of, or in the defense
         of  an  action  by a  Third  Party  related  to  patent  invalidity  or
         non-patentability   of  any  patent   application  or  patent  claiming
         Collaboration Technology licensed hereunder,  neither Party shall admit
         the  invalidity  or  non-patentability  of any Patent Right or take any
         other  action that may  diminish  Patent  Rights  within  Collaboration
         Technology  licensed  hereunder without the other Party's prior written
         consent. Wyeth-Ayerst agrees to provide Neurocrine with sufficient time
         to review,  comment and consult on all patent  applications and patents
         and  all  correspondence  to  and  from  the  various  patent  offices,
         including,  but not limited to, proposed  responses,  interferences and
         oppositions,  claiming  Neurocrine  Inventions,  Joint  Inventions  and
         Wyeth-Ayerst Inventions. The Parties agree to cooperate with each other
         and to use best  efforts  to  ensure  the  cooperation  of any of their
         respective personnel and licensee(s) or licensor(s) as might reasonably
         be requested in any such matters,  and shall sign any  necessary  legal
         papers and provide the prosecuting party with data or other information
         in support thereof. The Parties will confer on what action to take with
         respect  to  the  defense  of  infringement   proceedings  naming  both
         Wyeth-Ayerst  and  Neurocrine  or in  proceedings  to  enforce  patents
         claiming  Collaboration  Technology  licensed hereunder against a Third
         Party.  If the Parties cannot agree on the course of action to be taken
         in the filing,  prosecution,  maintenance,  or enforcement of any Joint
         Invention or  Wyeth-Ayerst  Invention,  Wyeth-Ayerst's  decisions shall
         control.  If the  Parties  cannot  agree on the  course of action to be
         taken  in the  filing,  prosecution,  maintenance,  or  enforcement  of
         Neurocrine Invention, Neurocrine's decisions shall control.


                                ARTICLE FOURTEEN
                                  MISCELLANEOUS

14.1     Disputes.  If the  Parties  are unable to resolve a dispute  among them
         informally,  Wyeth-Ayerst  and  Neurocrine,  by  written  notice to the
         other,  may have such dispute  referred to their  respective  executive
         officers   designated   for   attempted   resolution   by  good   faith
         negotiations:

         For Wyeth-Ayerst:       President of Wyeth-Ayerst 
                                 Research for development issues

                                 President Wyeth-Ayerst Global Pharmaceuticals 
                                 for commercialization issues


         For Neurocrine:         President and Chief Executive Officer

         Any such dispute shall be submitted to the  above-designated  executive
         officers  no later than  thirty  (30) days  following  such  request by
         either  Wyeth-Ayerst  or  Neurocrine.   In  the  event  the  designated
         executive  officers  are not able to resolve  any such  dispute  within
         [***]  after  submission  of the  dispute to such  executive  officers,
         Wyeth-Ayerst  or  Neurocrine,  as the case may be, may pursue what ever
         measures are legally  available to them to resolve  such  dispute.  All
         negotiations  pursuant  to  this  Section  14.1  shall  be  treated  as
         compromise and settlement negotiations.  Nothing said or disclosed, nor
         any document produced,  in the course of such negotiations which is not
         otherwise  independently  discoverable  shall be offered or received as
         evidence  or used  for  impeachment  or for any  other  purpose  in any
         current or future arbitration or litigation.

14.2     Assignment.  Neither this Agreement nor any interest hereunder shall be
         assignable  by either Party  without the prior  written  consent of the
         other Party,  except for  assignment  by operation of law in connection
         with a merger of a Party with or into another  Person.  This  Agreement
         shall be  binding  upon the  successors  and  permitted  assigns of the
         Parties  and the name of a Party  appearing  herein  shall be deemed to
         include the names of such Party's  successors and permitted  assigns to
         the extent  necessary  to carry out the intent of this  Agreement.  Any
         assignment not in accordance with this Section 14.2 shall be void.

14.3     Further Actions. Each Party agrees to execute,  acknowledge and deliver
         such  further  instruments,  and to do all such other  acts,  as may be
         necessary or  appropriate in order to carry out the purposes and intent
         of the Agreement.

14.4     Force Majeure.  No Party shall be liable to the other Party for loss or
         damages or shall have any right to  terminate  this  Agreement  for any
         default  or delay  attributable  to any  Force  Majeure,  if the  Party
         affected shall give prompt notice of any such cause to the other Party.
         The Party  giving such notice  shall  thereupon be excused from such of
         its obligations hereunder as it is thereby disabled from performing for
         so long as it is so disabled,  provided,  however,  that such  affected
         Party  commences  and  continues  to use  its  Commercially  Reasonable
         Efforts to cure such cause.

14.5     Correspondence and Notices.

         (a)      Ordinary Notices. Correspondence,  reports, documentation, and
                  any other  communication in writing between the Parties in the
                  course of ordinary  implementation  of this Agreement shall be
                  delivered  by hand,  sent by facsimile  transmission  (receipt
                  verified),  or by airmail to the employee or representative of
                  the  other  Party who is  designated  by such  other  Party to
                  receive such written communication.

         (b)      Extraordinary   Notices.   Extraordinary   notices  and  other
                  communications hereunder (including,  without limitation,  any
                  notice  of  force  majeure,  breach,  termination,  change  of
                  address,   exercise   of   rights  to   negotiate   additional
                  agreements,  etc.)  shall be in  writing  and  shall be deemed
                  given if delivered  personally  or by  facsimile  transmission
                  (receipt  verified),  mailed by registered  or certified  mail
                  (return  receipt  requested),  postage  prepaid,  or  sent  by
                  nationally  recognized express courier service, to the Parties
                  at the  following  addresses  (or at such other  address for a
                  Party as shall be specified by like notice, provided, however,
                  that notices of a change of address  shall be  effective  only
                  upon receipt thereof):

                  All correspondence to Wyeth-Ayerst shall be addressed as 
                  follows:

                        Wyeth-Ayerst Laboratories
                        555 East Lancaster Avenue
                        St. Davids, Pennsylvania  19087
                        Attn: Senior Vice President, Global Business Development
                        Fax:  (610) 688-9498

                                with a copy to:
                                American Home Products Corporation
                                5 Giralda Farms
                                Madison, New Jersey  07940
                                Attn:  Senior Vice President and General Counsel
                                Fax:  (973) 660-7156

                  All   correspondence  to  Neurocrine  shall  be  addressed  as
                  follows:

                        Neurocrine Biosciences, Inc.
                        10555 Science Park Road
                        San Diego, California 9211-1102
                        Attn: Director Product Licensing
                        Fax: 619-658-7602

                                with a copy to:
                                Neurocrine Biosciences, Inc.
                                10555 Science Park Road
                                San Diego, California 9211-1102
                                Attn:  Corporate Secretary
                                Fax: 619-658-7605

14.6     Amendment. No amendment, modification or supplement of any provision of
         this Agreement  shall be valid or effective  unless made in writing and
         signed by a duly authorized officer of each Party.

14.7     Waiver.  No  provision  of the  Agreement  shall be  waived by any act,
         omission or knowledge  of a Party or its agents or employees  except by
         an instrument in writing expressly waiving such provision and signed by
         a duly authorized officer of the waiving Party.


14.8     Counterparts.   This  Agreement  may  be  executed  in  any  number  of
         counterparts, each of which need not contain the signature of more than
         one Party but all such counterparts taken together shall constitute one
         and the same agreement.

14.9     Descriptive  Headings.  The descriptive  headings of this Agreement are
         for convenience  only, and shall be of no force or effect in construing
         or interpreting any of the provisions of this Agreement.

14.10    Governing Law. This Agreement  shall be governed by and  interpreted in
         accordance with the substantive laws of the State of Delaware  (without
         regard to conflict of law  principles) and the Parties hereby submit to
         the  exclusive  jurisdiction  of the  federal  courts  of the  state of
         California.

14.11    Severability.  In the event that any clause or portion  thereof in this
         Agreement   is  for  any  reason  held  to  be   invalid,   illegal  or
         unenforceable,  the same  shall not  affect  any other  portion of this
         Agreement, as it is the intent of the Parties that this Agreement shall
         be construed in such fashion as to maintain its existence, validity and
         enforceability to the greatest extent possible. In any such event, this
         Agreement  shall be construed as if such clause of portion  thereof had
         never  been  contained  in this  Agreement,  and there  shall be deemed
         substituted  therefor such  provision as will most nearly carry out the
         intent of the Parties as  expressed  in this  Agreement  to the fullest
         extent  permitted  by  applicable  law  unless  doing so would have the
         effect of materially  altering the right and obligations of the Parties
         in which event this  Agreement  shall  terminate and all the rights and
         obligations  granted to the Parties  hereunder shall cease and be of no
         further force and effect.

14.12    Entire  Agreement  of  the  Parties.  This  Agreement  constitutes  and
         contains the complete,  final and exclusive understanding and agreement
         of  the  Parties  and  cancels  and   supersedes   any  and  all  prior
         negotiations, correspondence,  understandings and agreements including,
         without limitation, the Prior Agreement, whether oral or written, among
         the Parties respecting the subject matter hereof and thereof.

14.13    Independent  Contractors.  The  relationship  between  Wyeth-Ayerst and
         Neurocrine created by this Agreement is one of independent  contractors
         and neither Party shall have the power or authority to bind or obligate
         the other except as expressly set forth in this Agreement.

14.14    No Trademark  Rights.  Expect as otherwise  provided herein,  no right,
         express or implied,  is granted by this  Agreement to use in any manner
         the name "Neurocrine  Biosciences"  "Wyeth-Ayerst,"  or any other trade
         name or trademark of the other Party or its  Affiliates  in  connection
         with the performance of this Agreement.

14.15    Accrued  Rights;  Surviving  Obligations.  Unless  explicitly  provided
         otherwise in this Agreement, termination,  relinquishment or expiration
         of the  Agreement  for any  reason  shall be without  prejudice  to any
         rights  which  shall have  accrued to the benefit to any Party prior to
         such  termination,  relinquishment  or  expiration,  including  damages
         arising from any breach hereunder. Such termination,  relinquishment or
         expiration  shall not  relieve  any Party  from  obligations  which are
         expressly  indicated  to  survive  termination  or  expiration  of  the
         Agreement,  including,  without limitation, those obligations set forth
         in Articles Ten, Eleven and Twelve and Sections 5.8, 5.9, 9.4, 14.1 and
         14.5 hereof.

14.16    Export.  Notwithstanding anything to the contrary set forth herein, all
         obligations  of  Neurocrine  and  Wyeth-Ayerst  are  subject  to  prior
         compliance  with United States and foreign export  regulations and such
         other  United  States  and  foreign  laws  and  regulations  as  may be
         applicable  and  to  obtaining  all  necessary  approvals  required  by
         applicable agencies of the governments of the United States and foreign
         jurisdictions.  Neurocrine and  Wyeth-Ayerst  will  co-operate with one
         another and provide  assistance to one another as reasonably  necessary
         to obtain any required approvals.

         IN WITNESS WHEREOF, duly authorized representatives of the Parties have
duly executed this Agreement to be effective as of the Effective Date.

AMERICAN HOME PRODUCTS CORPORATION,            NEUROCRINE BIOSCIENCES, INC.
acting through its
WYETH-AYERST LABORATORIES DIVISION



By /s/ Egon Berg                               By: /s/ Gary Lyons
Name:  Egon Berg                               Name:   Gary Lyons
Title: Vice President &                        Title:  President & 
       Associate General Counsel                       Chief Executive Officer
                            
Date: 03/02/98                                 Date: 03/02/98







                                    EXHIBIT A
                                  TRANSPORTERS
                                      [***]


                                    EXHIBIT B
                                  LEAD COMPOUND
                                      [***]


                                    EXHIBIT C
                                  PATENT RIGHTS
                                      [***]


                                    EXHIBIT D
                                 OHSU AGREEMENT
                                      [***]


                                    EXHIBIT E
                               THIRD PARTY PATENTS
                                      [***]


                                    EXHIBIT F
                          OTHER NEUROCRINE OBLIGATIONS
                                      [***]