EXHIBIT 10.1
                                                                  ------------


                                                              EMPLOYMENT
                                                     AGREEMENT dated as of April
                                                     1,  1998  (the   "Effective
                                                     Date"),   between  SYNAPTIC
                                                     PHARMACEUTICAL CORPORATION,
                                                     a Delaware corporation (the
                                                     "Company"),  and THERESA A.
                                                     BRANCHEK (the
                                                     "Employee").


                  Immediately  prior to the  Effective  Date,  the  Employee was
employed by the Company as Vice President for New Technologies and Pharmacology.
Effective  as of the  Effective  Date,  the  Employee  is being  promoted to the
position of Vice  President for Research.  As a result of her  employment by the
Company, the Employee possesses special and particular knowledge of the business
and  operations  of the Company and of the  industry in which it  operates.  The
Company  and the  Employee  desire  to set  forth in  writing  the  terms of the
Employee's  employment  by the  Company in the  capacity of Vice  President  for
Research.

                  ACCORDINGLY,  in  consideration  of the mutual  covenants  and
obligations hereinafter set forth, the parties hereto agree as follows:

                  1. Employment.  The Company  hereby  employs the Employee, and
the  Employee hereby  accepts such employment by  the Company, on  the terms and
subject to the conditions hereinafter set forth.

                  2. Term.  Subject to earlier  termination as provided  herein,
the  employment  of  the  Employee  hereunder  shall  be for a  one-year  period
commencing on the Effective  Date,  and ending on the first  anniversary  of the
Effective Date; provided,  however, that commencing as of such first anniversary
and on each anniversary  thereafter,  unless either party hereto gives the other
party at least 90 days'  prior  written  notice  of its or her  election  not to
extend the period of the  Employee's  employment  hereunder,  such period  shall
automatically  be extended for an additional  one-year  period on the same terms
and conditions set forth herein,  unless  otherwise  agreed upon by the parties.
For  convenience  of reference,  such period of  employment,  as the same may be
extended as aforesaid, is referred to herein as the "Employment Period."

                  3.  Duties.  (a) During the  Employment  Period,  the Employee
shall be  employed  as Vice  President  for  Research  of the  Company and shall
perform  such duties for the  Company  consistent  with such  position as may be
assigned to her from time to time by the President of the Company.

       (b) The Employee shall perform her duties hereunder at the offices of the
Company in Paramus, New Jersey; provided,  however, that the Company may require
the  Employee  to travel in  connection  with the  performance  of such  duties.
Anything  contained  herein  to the  contrary  notwithstanding,  if the  Company
requires the Employee to be based anywhere other than within a 50-mile radius of
New York City and notifies the Employee in writing that her continued

                                        1

<PAGE>



employment by the Company is conditional  upon such  relocation and the Employee
refuses to so  relocate,  then any  Termination  of  Employment  of the Employee
resulting therefrom,  whether initiated by the Company or by the Employee, shall
constitute a Termination Without Cause.

                  4. Time to be Devoted to Employment.  Except for vacations and
absences due to temporary  illness,  during the Employment  Period, the Employee
shall devote all of her business time, attention and energies to the performance
of her duties under this Agreement.  During the Employment  Period, the Employee
shall not be engaged in any other business  activity  which,  in the judgment of
the Company,  conflicts  with the duties of the Employee  under this  Agreement,
whether or not such  activity  is pursued  for gain,  profit or other  pecuniary
advantage.

                  5.       Compensation; Reimbursement.

                           (a)      Base Salary.  During  the Employment Period,
the  Company  shall pay to the  Employee a base  salary of  $200,000  per annum,
subject to increase by the Board of Directors of the Company, in its discretion.
For convenience of reference,  such base salary, as the same may be increased as
aforesaid,  is referred to herein as the "Base Salary." The Base Salary shall be
payable in such  installments  (but not less  frequent  than  monthly) as is the
policy of the Company generally with respect to its employees.

                           (b)      Signing Bonus.  On the Effective Date, or as
soon  thereafter  as may be  reasonably  practicable,  the Company shall pay the
Employee an initial cash bonus (the "Signing Bonus") of $25,000.

                           (c)      Annual Performance Bonus. In addition to the
Signing Bonus,  the Employee shall be eligible to receive for each calendar year
during the Employment  Period a cash bonus in an amount  determined by the Board
of Directors of the Company prior to the Effective  Date and at the beginning of
each  subsequent  calendar year, in each case subject to the  achievement of the
goals  set  prior  to the  Effective  Date  and at the  beginning  of each  such
subsequent year,  respectively,  by the President of the Company. Each such cash
bonus, if earned,  will be payable to the Employee within  forty-five days after
the end of the  calendar  year  in  respect  of  which  such  bonus  is  earned.
Additional bonuses may be approved by the Board of Directors of the Company,  in
its discretion.

                           (d)      Benefits.  During the Employment Period, the
Employee  shall be entitled to such benefits as are generally  made available to
other employees of the Company and to such additional  benefits as are generally
made  available to employees of the Company at  substantially  the same level of
employment as the Employee.

                           (e)      Reimbursement of Expenses.    During     the
Employment Period, the Company shall reimburse the Employee,  in accordance with
the  policies  and  practices  of the Company in effect from time to time during
such Period,  for all  reasonable  and  necessary  traveling  expenses and other
disbursements incurred by her for or on behalf of the Company in connection with
the perfor mance of her duties hereunder (such expenses being referred to herein
as "Reimbursable  Expenses") upon presentation by the Employee to the Company of
appropriate documentation therefor.


                                        2

<PAGE>



                           (f)      Option Grants.  (i)   The  Employee shall be
granted an option to purchase 20,000 shares of Common Stock of the Company, $.01
par value (the  "Common  Stock"),  at a price per share equal to the fair market
value of the Common  Stock as of the date the option is granted.  Such grant (A)
shall be  subject to the  Company's  1996  Incentive  Plan and (B) shall be made
pursuant  to the terms and  conditions  of the  Company's  form of stock  option
agreement.  Such stock option  agreement will provide,  among other things,  for
four-year  vesting  of the option  covered  thereby,  with the  option  becoming
exercisable for 25% of the shares subject to such option on each  anniversary of
the Effective Date.

                  6.       Termination of Employment.

                           (a)      General.  The  Company  may  terminate   the
Employee's  employment  hereunder  at any time for any reason.  The Employee may
terminate her employment  hereunder pursuant to a Resignation for Good Reason, a
Voluntary  Termination or a Disability  Termination.  The Employee's  employment
shall terminate  automatically upon her death. Any termination of the Employee's
employment is referred to herein as a "Termination of Employment."

                           (b)      Termination Notice.    The  Company  or  the
Employee  may  initiate a  Termination  of  Employment  in any manner  permitted
hereunder by giving the other party  written  notice  thereof (the  "Termination
Notice").

                           (c)      Termination Date.  The  effective  date (the
"Termination  Date") of any Termination of Employment  shall be deemed to be the
later of (i) the date on which the Termination Notice is given and (ii) the date
specified as the effective date in the Termination  Notice;  provided,  however,
that in the case of the Employee's death, the Termination Date shall be her date
of death.

                  7.       Termination by the Company.

                           (a)      Termination for Cause.  Any  Termination  of
Employment  initiated  by the  Company  upon the  occurrence  of an  event  that
constitutes  Cause shall be a  "Termination  for  Cause."  For  purposes of this
Agreement,  the term "Cause" shall mean (i) the  Employee's  willful  failure to
perform  those duties that the Employee is required or expected to perform as an
employee of the Company under Section 3 hereof, provided that the Employee shall
have been given  written  notice of such  failure  and shall not have cured such
failure  during the 30-day period  following  such notice,  (ii) the  Employee's
consistent failure over a substantial period of time to perform competently such
duties,  provided that the Employee shall have been given written notice of such
failure and shall not have cured such failure during the 30-day period following
such  notice,  (iii)  the  Employee's  conviction  of a  crime  involving  moral
turpitude,  dishonesty,  theft,  unethical  business  conduct  or  conduct  that
significantly  impairs  the  reputation  of the  Company or (iv) the  Employee's
failure  to devote all of her  business  time,  attention  and  energies  to the
performance of her duties  hereunder.  In the event of a Termination  for Cause,
the Termination Notice given to the Employee by the Company shall state that the
Termination of Employment is "for Cause."


                                        3

<PAGE>



                           (b)      Termination Without Cause.  Any  Termination
of Employment  initiated by the Company (other than a Termination for Cause or a
Disability Termination) shall be a "Termination Without Cause."

                  8.       Termination by the Employee.

                           (a)      Resignation for Good Reason. Any Termination
of Employment  initiated by the Employee within 90 days following the occurrence
of any of the following events shall be a "Resignation for Good Reason":

                  (i)  subsequent  to a  Change  in  Control,  and  without  the
         Employee's express written consent,  (A) the assignment to the Employee
         of any duties inconsistent with her position, duties,  responsibilities
         and status within the Company prior to such Change in Control,  (B) any
         material change in the Employee's  titles or offices as in effect prior
         to such  Change in Control or (C) any removal of the  Employee  from or
         any failure to re-elect the Employee to any material  position  held by
         her prior to such Change in Control;

                  (ii)  subsequent  to a Change in Control,  a reduction  in the
         Employee's Base Salary or a termination of the Employee's participation
         in any bonus plan or program (or a  substantial  reduction in the level
         of such  participation)  as in effect on the  Effective  Date or as the
         same may be  increased  after the  Effective  Date and in effect at the
         time;

                  (iii)  subsequent  to a Change in  Control,  and  without  the
         Employee's  express written consent,  any requirement that the Employee
         be based anywhere other than within a 50-mile radius of New York City;

                  (iv)  subsequent  to a Change in  Control,  the failure by the
         Company to  continue  the  Employee's  participation  in any benefit or
         compensation  plan, life insurance plan,  health-and-  accident plan or
         disability plan in which the Employee is  participating  at the time of
         such  Change  in  Control  (or in plans  providing  the  Employee  with
         substantially  similar or more favorable benefits) or the taking of any
         action by the  Company  which  would  materially  adversely  affect the
         Employee's   participation  in  or  materially  reduce  the  Employee's
         benefits  under  any of such  plans  or  deprive  the  Employee  of any
         material  fringe  benefit  enjoyed by the  Employee at the time of such
         Change in Control; or

                  (v)  subsequent  to a Change in  Control,  the  failure by the
         Company to obtain  the  assumption  of the  agreement  to perform  this
         Agreement by any successor as contemplated by Section 16.

In the event of a Resignation for Good Reason,  the Termination  Notice given to
the Company by the Employee shall state that the  Termination of Employment is a
"Resignation for Good Reason."

                     (b)  Other Termination by the Employee.  Any Termination of
Employment  initiated by the Employee  (other than a  Termination  of Employment
resulting  from  the  Employee's  death,  a  Resignation  for Good  Reason  or a
Disability Termination) shall be a "Voluntary Termination."


                                        4

<PAGE>



                  9. Termination by the Company or by the Employee -- Disability
Termination.  Any  Termination  of  Employment  resulting  from  the  Employee's
Disability shall be a "Disability  Termination." For purposes of this Agreement,
the term  "Employee's  Disability"  shall mean the  Employee's  illness or other
physical or mental  disability  that prevents the Employee from  performing  her
duties hereunder for a period of 90 days in any 180-day period.  In the event of
a Disability Termination, the Termination Notice given to one party by the other
party  shall  state  that  the   Termination  of  Employment  is  a  "Disability
Termination."

                  10. Effect of Termination of Employment. (a) In the Event of a
Termination of Employment  (other than a Termination of Employment  contemplated
by Section 11(a)),  neither the Employee nor her estate or  beneficiaries  shall
have any  further  rights or claims  against the  Company  under this  Agreement
except the right to receive:

                  (i) the portion of the Base Salary which  accrued with respect
         to the period prior to the  Termination  Date but which remained unpaid
         as of the Termination Date;

                  (ii) the aggregate amount of Reimbursable  Expenses which were
         incurred prior to the Termination Date but which were not reimbursed by
         the Company as provided in Section 5(e) prior to the Termination  Date;
         and

                  (iii) any other benefits to which the Employee may be entitled
         upon such  Termination  of  Employment  under the plans,  programs  and
         policies of the Company then in effect, which benefits shall be payable
         in accordance with the terms of such plans, programs and policies;

provided,  however,  that if the  Termination  of  Employment  is  pursuant to a
Termination Without Cause, then, in addition to the amounts computed pursuant to
the foregoing  provisions  of this Section  10(a),  the Employee  shall have the
right to receive as severance  compensation an amount (the  "Severance  Amount")
equal to 50% of one year's Base Salary,  such Severance  Amount to be payable at
the same times at which and in the same  manner in which the Base  Salary  would
have  been  payable  to the  Employee  had the  Termination  of  Employment  not
occurred.

          (b)   The Employee shall not be required to mitigate the amount of any
payment  provided  for  in  this  Section  10 by  seeking  other  employment  or
otherwise,  and no payment or benefit  provided  for in this Section 10 shall be
reduced by compensation  earned by the Employee as a result of her employment by
another employer following the Termination Date, or otherwise.

                  11. Effect of Termination of Employment  following a Change in
Control.  (a) In the event that the  Employee's  employment  with the Company is
terminated  in  contemplation  of, or at any time within one year  following,  a
Change in Control, and such termination  constitutes a Termination Without Cause
or a  Resignation  for Good  Reason,  neither  the  Employee  nor her  estate or
beneficiaries  shall have any further rights or claims against the Company under
this Agreement other than the following:


                                        5

<PAGE>



                  (i) the right to receive all amounts and benefits to which the
         Employee  would be  entitled  under  Section 10 upon a  Termination  of
         Employment; and

                  (ii) all stock  options,  stock  bonus  awards and  restricted
         stock grants relating to securities of the Company held by the Employee
         on the Termination  Date shall become  exercisable or vest, as the case
         may be, on the Termination Date,  notwithstanding any provisions in any
         such stock  options,  stock bonus awards or restricted  stock grants or
         the plans covering the same to the contrary, and all rights to exercise
         such stock  options  shall  remain  exercisable  by the  Employee for a
         period of not less than 120 days after the Termination Date.

If the benefits payable hereunder, together with other payments in the nature of
compensation  to or with respect to the Employee,  would otherwise be subject to
the excise taxes  imposed  under  Section  280G of the Internal  Revenue Code of
1986, as amended ("Code"), and if the net value of such benefits and payments in
the nature of  compensation,  after  reduction for such taxes,  is less than the
aggregate  value of the  benefits  and  payments  in the nature of  compensation
determined  as if such  amounts had been $1.00 less than a maximum  amount which
could be paid without  imposition  of excise  taxes,  then the benefits  payable
hereunder  shall be reduced to highest  amount such that such excise taxes shall
not be imposed with respect to the benefits or the other  payments in the nature
of  compensation.  It is the  intention  of this  provision  to reduce  benefits
payable  hereunder only if the Employee would be in a superior  position  taking
into  account  such  excise  taxes than if such  payments  were  made,  and such
reduction shall, in any event, be the least amount in order that the Employee be
better off with the reduction than before such reduction. The calculation of the
value of  benefits  payable  hereunder  and  other  payments  in the  nature  of
compensation,  and the  implications  of the excise tax rules of Section 280G of
the Code,  shall be  determined  by the  Company in good faith  based on written
advice of a national accounting firm.

       (b)      The Employee shall not be required to mitigate the amount of any
payment  provided  for  in  this  Section  11 by  seeking  other  employment  or
otherwise,  and no payment or benefit  provided  for in this Section 11 shall be
reduced by compensation  earned by the Employee as a result of her employment by
another employer following the Termination Date, or otherwise.

      (c) As used  herein,  the term  "Change in Control" shall mean a change in
control of the  Company of a nature  that would be  required  to be  reported in
response to Item 1 of Form 8-K promulgated under the Securities  Exchange Act of
1934, as amended (the "Exchange  Act"), if the Company were at that time subject
to such reporting requirements of the Exchange Act; provided, however, that such
term shall in any event be deemed to have  occurred if (i) any "person" (as such
term is used in Sections  13(d) and 14(d) of the Exchange Act) is or becomes the
"beneficial  owner" (as defined in Rule 13d-3 under the Exchange Act),  directly
or  indirectly,  of  securities of the Company  representing  35% or more of the
combined  voting power of the  Company's  then  outstanding  securities  or (ii)
during any one-year period or any period of two consecutive  years,  individuals
who at the beginning of any such period constitute the Board of Directors of the
Company cease for any reason to constitute at least a majority thereof as of the
end of such period unless the election,  or the  nomination  for election by the
Company's stockholders,  of each new director was approved by a vote of at least
two-thirds  of the  directors  of the  Company  then  still in  office  who were
directors at the beginning of such period.


                                        6

<PAGE>



                  12.  Non-solicitation  of Employees.  The Employee agrees that
during the term of the Employee's  employment  with the Company and for a period
of two years after the termination of the Employee's employment with the Company
for any reason, the Employee shall not directly or indirectly  recruit,  solicit
or otherwise  induce or attempt to induce any  employees of the Company to leave
the employment of the Company.

                  13. Non-competition.  The Employee agrees that during the term
of the  Employee's  employment  with the  Company  and for a period of two years
after the  termination  of the  Employee's  employment  with the Company for any
reason,  the  Employee  shall not  directly or  indirectly,  except as a passive
investor in publicly held companies and except for investments  held at the date
hereof,  engage in competition with the Company or any of its  subsidiaries,  or
own or control any interest  in, or act as director,  officer or employee of, or
consultant  to, any firm,  corporation  or  institution  directly or  indirectly
engaged in competition with the Company or any of its subsidiaries. For purposes
of this Section 13,  "competition  with the Company or any or its  subsidiaries"
shall mean  research  focused  upon or  directed  toward the  specific  class of
molecular  targets  known as "G  protein-  coupled  receptors"  and/or  research
otherwise  involving the Company's  technology platform at the Termination Date.
The   Employee's   carrying   out   teaching,   research   or   other   academic
responsibilities  at  an  academic  institution  shall  not  be  deemed  to be a
violation of this Section 13,  provided  that such  teaching,  research or other
responsibilities  (i) are carried out solely on behalf of such  institution  and
not on behalf of, for the  benefit of or in  collaboration  with any  commercial
enterprise and (ii) do not violate any other  provision of this Agreement or any
other  agreement  between  the  Employee  and the  Company.  In the  event  of a
Termination  of  Employment  to which the  provisions  of Section 11 apply,  the
period of this non-competition  restriction will be limited to the period during
which the Employee is receiving the Severance Amount provided in Section 10(a).

                  14.  Notices.  All  notices or other  communications  that are
required or permitted  hereunder shall be in writing and shall be deemed to have
been  given  if (a)  personally  delivered  or sent by  telecopier,  (b) sent by
nationally-recognized  overnight  courier or (c) sent by registered or certified
mail, postage prepaid, return receipt requested, addressed as follows:

                  if to the Employee, to her at:

                           518 Standish Road
                           Teaneck, New Jersey  07666

                  if to the Company, to it at:

                           215 College Road
                           Paramus, New Jersey  07652
                           Attention:  President
                           Telecopier:  201-261-0623

or to such  other  address  as the party to whom  notice is to be given may have
furnished  to each  other  party in  writing in  accordance  herewith.  Any such
communication  shall be deemed  to have been  received  (i) when  delivered,  if
personally  delivered,  sent by  telecopier  or  sent by  nationally-recognized,
overnight courier and (ii) on the third Business Day following the date on which
the piece


                                        7

<PAGE>



of mail  containing  such  communication  is  posted,  if sent by mail.  As used
herein, the term "Business Day" means a day that is not a Saturday,  a Sunday or
a day on  which  banking  institutions  in the  city  to  which  the  notice  or
communication is to be sent are not required to be open.

                  15. Entire Agreement;  Amendments. This Agreement contains the
entire  agreement  between the parties hereto with respect to the subject matter
hereof and supersedes all prior or contemporaneous negotiations, correspondence,
understandings  and agreements  between the parties with respect  thereto.  This
Agreement may be amended only by an agreement in writing  signed by both parties
hereto.  Anything  contained  herein  to  the  contrary   notwithstanding,   the
provisions  of  Sections  10  and 11  shall  survive  the  expiration  or  early
termination of the Employment Period.

                  16.  Assignment.  This  Agreement  is  personal in its nature.
Accordingly,  neither  party  hereto  shall,  without  the consent of the other,
assign this Agreement or any rights or obligations hereunder to any other person
or entity.

                  17.  Benefits of Agreement.  The  provisions of this Agreement
shall be binding  upon and inure to the  benefit  of the  heirs,  beneficiaries,
executors,  administrators  and  permitted  assigns  of  the  Employee  and  the
successors and permitted assigns of the Company.

                  18. Obligation of the Company's  Successors.  Any successor to
substantially  all of the  Company's  assets  and  business,  whether by merger,
consolidation,  purchase of assets or otherwise, shall succeed to the rights and
obligations  of the  Company  hereunder.  The  Company  shall  require  any such
successor,  by agreement in form and substance  satisfactory to the Employee, to
expressly  assume and agree to perform this  Agreement in the same manner and to
the same  extent  that the  Company  would be  required to perform it if no such
succession had taken place.  The failure of the Company to obtain such agreement
prior to the  effectiveness  of any such  succession  shall be a breach  of this
Agreement  and shall  entitle the  Employee  to receive  from the Company or its
successor the same amounts and benefits  that the Employee  would be entitled to
receive  under  Sections  11(a)(i) and  11(a)(ii)  upon a  Resignation  for Good
Reason.  For purposes of implementing the immediately  preceding  sentence,  the
date on  which  any such  succession  becomes  effective  shall  be  deemed  the
Termination Date.

                  19. Waiver of Breach.  A waiver of any breach of any provision
of this  Agreement  shall not  constitute  or  operate  as a waiver of any other
breach of such provision or of any other  provision,  and any failure to enforce
any provision  hereof shall not operate as a waiver of such  provision or of any
other provision.

                  20. Execution in Counterparts.  This Agreement may be executed
in one or more counterparts,  each of which shall be deemed an original, but all
of which shall constitute one and the same instrument.

                  21. Headings.   The headings of sections in this Agreement are
for convenience  only, are not a part of this Agreement and shall not affect the
construction of the provisions of this Agreement.


                                        8

<PAGE>



                  22.  Governing Law. This  Agreement  shall be governed by, and
construed and enforced in accordance  with,  the laws of the State of New Jersey
without giving effect to principles of conflicts of laws.

                  23.  Enforceability.  In the event that any  provision of this
Agreement  is  determined  to  be  partially  or  wholly  invalid,   illegal  or
unenforceable  in any  jurisdiction,  then  such pro  vision  shall,  as to such
jurisdiction,  be modified or  restricted  to the extent  necessary to make such
provision  valid,  binding  and  enforceable,  or, if such  provision  cannot be
modified or restricted,  then such provision shall, as to such jurisdiction,  be
deemed to be excised from this Agreement;  provided,  however,  that the binding
effect and enforceability of the remaining provisions of this Agreement,  to the
extent that the economic  benefits  conferred upon the parties by virtue of this
Agreement remain substantially unimpaired,  shall not be affected or impaired in
any manner, and that any such invalidity,  illegality or  unenforceability  with
respect to such  provisions  shall not invalidate or render  unenforceable  such
provision in any other jurisdiction.

                                        9

<PAGE>


                  IN  WITNESS  WHEREOF,  the  parties  have duly  executed  this
Agreement as of the date first above written.



                                            SYNAPTIC PHARMACEUTICAL CORPORATION


                                               /s/ Kathleen P. Mullinix
                                            By:--------------------------------
                                                Name:  Kathleen P. Mullinix
                                                Title: Chairman, President and
                                                        Chief Executive Officer


                                                 /s/ Theresa A. Branchek
                                                 ------------------------------
                                                 Theresa A. Branchek




                                       10