<PAGE>

                                                                EXHIBIT 25.1


                               POWER OF ATTORNEY


        KNOW ALL YE PERSONS BY THESE PRESENTS, that the undersigned does hereby
make, constitute and appoint Harry H. Penner, Jr., and Stephen R. Davis, each
his attorney-in-fact and agent with full power of substitution and
resubstitution for him and in his name, place and stead, in any and all
capacities, to execute for him and on his behalf an Annual Report pursuant to
Section 13 of the Securities and Exchange Act of 1934, as amended, on form 10-K
relating to the fiscal year ended December 31, 1996, of Neurogen Corporation
(the "Company"), and any and all amendments to the foregoing Annual Report on
Form 10-K, which amendments may make such changes in the Annual Report on Form
10-K as such attorney-in-fact deems appropriate, and any other documents and
instruments incidental thereto, and to file the same, with all exhibits thereto
and all documents in connection therewith, with the Securities and Exchange
Commission and the National Association of Securities Dealers, Inc., granting
unto said attorney-in-fact and agent, full power and authority to do and perform
each and every act and thing requisite and necessary to be done in and about the
premises, as fully to all intents and purposes as the undersigned might or could
do in person, hereby ratifying and confirming all that said attorney-in-fact and
agent, or his substitute or substitutes, may lawfully do or cause to be done by
virtue hereof.

        IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney
this 7th day of March, 1997.



                                        /s/ FRANK C. CARLUCCI
                                        ----------------------------
                                            Frank C. Carlucci
<PAGE>



                               POWER OF ATTORNEY


        KNOW ALL YE PERSONS BY THESE PRESENTS, that the undersigned does hereby
make, constitute and appoint Harry H. Penner, Jr., and Stephen R. Davis, each
his attorney-in-fact and agent with full power of substitution and
resubstitution for him and in his name, place and stead, in any and all
capacities, to execute for him and on his behalf an Annual Report pursuant to
Section 13 of the Securities and Exchange Act of 1934, as amended, on form 10-K
relating to the fiscal year ended December 31, 1996, of Neurogen Corporation
(the "Company"), and any and all amendments to the foregoing Annual Report on
Form 10-K, which amendments may make such changes in the Annual Report on Form
10-K as such attorney-in-fact deems appropriate, and any other documents and
instruments incidental thereto, and to file the same, with all exhibits thereto
and all documents in connection therewith, with the Securities and Exchange
Commission and the National Association of Securities Dealers, Inc., granting
unto said attorney-in-fact and agent, full power and authority to do and perform
each and every act and thing requisite and necessary to be done in and about the
premises, as fully to all intents and purposes as the undersigned might or could
do in person, hereby ratifying and confirming all that said attorney-in-fact and
agent, or his substitute or substitutes, may lawfully do or cause to be done by
virtue hereof.

        IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney
this 7th day of March, 1997.

                                        /s/ JOHN F. TALLMAN, PH.D.
                                        ----------------------------
                                            John F. Tallman, Ph.D.

<PAGE>




                               POWER OF ATTORNEY


        KNOW ALL YE PERSONS BY THESE PRESENTS, that the undersigned does hereby
make, constitute and appoint Harry H. Penner, Jr., and Stephen R. Davis, each
his attorney-in-fact and agent with full power of substitution and
resubstitution for him and in his name, place and stead, in any and all
capacities, to execute for him and on his behalf an Annual Report pursuant to
Section 13 of the Securities and Exchange Act of 1934, as amended, on form 10-K
relating to the fiscal year ended December 31, 1996, of Neurogen Corporation
(the "Company"), and any and all amendments to the foregoing Annual Report on
Form 10-K, which amendments may make such changes in the Annual Report on Form
10-K as such attorney-in-fact deems appropriate, and any other documents and
instruments incidental thereto, and to file the same, with all exhibits thereto
and all documents in connection therewith, with the Securities and Exchange
Commission and the National Association of Securities Dealers, Inc., granting
unto said attorney-in-fact and agent, full power and authority to do and perform
each and every act and thing requisite and necessary to be done in and about the
premises, as fully to all intents and purposes as the undersigned might or could
do in person, hereby ratifying and confirming all that said attorney-in-fact and
agent, or his substitute or substitutes, may lawfully do or cause to be done by
virtue hereof.

        IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney
this 7th day of March, 1997.

                                        /s/ ROBERT H. ROTH, PH.D.
                                        ----------------------------
                                            Robert H. Roth, Ph.D.


<PAGE>




                               POWER OF ATTORNEY


        KNOW ALL YE PERSONS BY THESE PRESENTS, that the undersigned does hereby
make, constitute and appoint Harry H. Penner, Jr., and Stephen R. Davis, each
his attorney-in-fact and agent with full power of substitution and
resubstitution for him and in his name, place and stead, in any and all
capacities, to execute for him and on his behalf an Annual Report pursuant to
Section 13 of the Securities and Exchange Act of 1934, as amended, on form 10-K
relating to the fiscal year ended December 31, 1996, of Neurogen Corporation
(the "Company"), and any and all amendments to the foregoing Annual Report on
Form 10-K, which amendments may make such changes in the Annual Report on Form
10-K as such attorney-in-fact deems appropriate, and any other documents and
instruments incidental thereto, and to file the same, with all exhibits thereto
and all documents in connection therewith, with the Securities and Exchange
Commission and the National Association of Securities Dealers, Inc., granting
unto said attorney-in-fact and agent, full power and authority to do and perform
each and every act and thing requisite and necessary to be done in and about the
premises, as fully to all intents and purposes as the undersigned might or could
do in person, hereby ratifying and confirming all that said attorney-in-fact and
agent, or his substitute or substitutes, may lawfully do or cause to be done by
virtue hereof.

        IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney
this 7th day of March, 1997.

                                        /s/ JEFFREY J. COLLINSON
                                        ----------------------------
                                            Jeffrey J. Collinson


<PAGE>




                               POWER OF ATTORNEY


        KNOW ALL YE PERSONS BY THESE PRESENTS, that the undersigned does hereby
make, constitute and appoint Harry H. Penner, Jr., and Stephen R. Davis, each
his attorney-in-fact and agent with full power of substitution and
resubstitution for him and in his name, place and stead, in any and all
capacities, to execute for him and on his behalf an Annual Report pursuant to
Section 13 of the Securities and Exchange Act of 1934, as amended, on form 10-K
relating to the fiscal year ended December 31, 1996, of Neurogen Corporation
(the "Company"), and any and all amendments to the foregoing Annual Report on
Form 10-K, which amendments may make such changes in the Annual Report on Form
10-K as such attorney-in-fact deems appropriate, and any other documents and
instruments incidental thereto, and to file the same, with all exhibits thereto
and all documents in connection therewith, with the Securities and Exchange
Commission and the National Association of Securities Dealers, Inc., granting
unto said attorney-in-fact and agent, full power and authority to do and perform
each and every act and thing requisite and necessary to be done in and about the
premises, as fully to all intents and purposes as the undersigned might or could
do in person, hereby ratifying and confirming all that said attorney-in-fact and
agent, or his substitute or substitutes, may lawfully do or cause to be done by
virtue hereof.

        IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney
this 7th day of March, 1997.

                                        /s/ JOHN SIMON
                                        ----------------------------
                                            John Simon


<PAGE>




                               POWER OF ATTORNEY


        KNOW ALL YE PERSONS BY THESE PRESENTS, that the undersigned does hereby
make, constitute and appoint Harry H. Penner, Jr., and Stephen R. Davis, each
his attorney-in-fact and agent with full power of substitution and
resubstitution for him and in his name, place and stead, in any and all
capacities, to execute for him and on his behalf an Annual Report pursuant to
Section 13 of the Securities and Exchange Act of 1934, as amended, on form 10-K
relating to the fiscal year ended December 31, 1996, of Neurogen Corporation
(the "Company"), and any and all amendments to the foregoing Annual Report on
Form 10-K, which amendments may make such changes in the Annual Report on Form
10-K as such attorney-in-fact deems appropriate, and any other documents and
instruments incidental thereto, and to file the same, with all exhibits thereto
and all documents in connection therewith, with the Securities and Exchange
Commission and the National Association of Securities Dealers, Inc., granting
unto said attorney-in-fact and agent, full power and authority to do and perform
each and every act and thing requisite and necessary to be done in and about the
premises, as fully to all intents and purposes as the undersigned might or could
do in person, hereby ratifying and confirming all that said attorney-in-fact and
agent, or his substitute or substitutes, may lawfully do or cause to be done by
virtue hereof.

        IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney
this 7th day of March, 1997.

                                        /s/ ROBERT M. GARDINER
                                        ----------------------------
                                            Robert M. Gardiner


<PAGE>




                               POWER OF ATTORNEY


        KNOW ALL YE PERSONS BY THESE PRESENTS, that the undersigned does hereby
make, constitute and appoint Harry H. Penner, Jr., and Stephen R. Davis, each
his attorney-in-fact and agent with full power of substitution and
resubstitution for him and in his name, place and stead, in any and all
capacities, to execute for him and on his behalf an Annual Report pursuant to
Section 13 of the Securities and Exchange Act of 1934, as amended, on form 10-K
relating to the fiscal year ended December 31, 1996, of Neurogen Corporation
(the "Company"), and any and all amendments to the foregoing Annual Report on
Form 10-K, which amendments may make such changes in the Annual Report on Form
10-K as such attorney-in-fact deems appropriate, and any other documents and
instruments incidental thereto, and to file the same, with all exhibits thereto
and all documents in connection therewith, with the Securities and Exchange
Commission and the National Association of Securities Dealers, Inc., granting
unto said attorney-in-fact and agent, full power and authority to do and perform
each and every act and thing requisite and necessary to be done in and about the
premises, as fully to all intents and purposes as the undersigned might or could
do in person, hereby ratifying and confirming all that said attorney-in-fact and
agent, or his substitute or substitutes, may lawfully do or cause to be done by
virtue hereof.

        IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney
this 7th day of March, 1997.

                                        /s/ ROBERT N. BUTLER, M.D.
                                        ----------------------------
                                            Robert N. Butler, M.D.


<PAGE>




                               POWER OF ATTORNEY


        KNOW ALL YE PERSONS BY THESE PRESENTS, that the undersigned does hereby
make, constitute and appoint Harry H. Penner, Jr., and Stephen R. Davis, each
his attorney-in-fact and agent with full power of substitution and
resubstitution for him and in his name, place and stead, in any and all
capacities, to execute for him and on his behalf an Annual Report pursuant to
Section 13 of the Securities and Exchange Act of 1934, as amended, on form 10-K
relating to the fiscal year ended December 31, 1996, of Neurogen Corporation
(the "Company"), and any and all amendments to the foregoing Annual Report on
Form 10-K, which amendments may make such changes in the Annual Report on Form
10-K as such attorney-in-fact deems appropriate, and any other documents and
instruments incidental thereto, and to file the same, with all exhibits thereto
and all documents in connection therewith, with the Securities and Exchange
Commission and the National Association of Securities Dealers, Inc., granting
unto said attorney-in-fact and agent, full power and authority to do and perform
each and every act and thing requisite and necessary to be done in and about the
premises, as fully to all intents and purposes as the undersigned might or could
do in person, hereby ratifying and confirming all that said attorney-in-fact and
agent, or his substitute or substitutes, may lawfully do or cause to be done by
virtue hereof.

        IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney
this 7th day of March, 1997.

                                        /s/ BARRY M. BLOOM
                                        ----------------------------
                                            Barry M. Bloom


<PAGE>




                               POWER OF ATTORNEY


        IN WITNESS WHEREOF, the undersigned has executed this Poser of Attorney
this 7th day of March, 1997.

        KNOW ALL YE PERSONS BY THESE PRESENTS, that the undersigned does hereby
make, constitute and appoint Harry H. Penner, Jr., and Stephen R. Davis, each
his attorney-in-fact and agent with full power of substitution and
resubstitution for him and in his name, place and stead, in any and all
capacities, to execute for him and on his behalf an Annual Report pursuant to
Section 13 of the Securities and Exchange Act of 1934, as amended, on form 10-K
relating to the fiscal year ended December 31, 1996, of Neurogen Corporation
(the "Company"), and any and all amendments to the foregoing Annual Report on
Form 10-K, which amendments may make such changes in the Annual Report on Form
10-K as such attorney-in-fact deems appropriate, and any other documents and
instruments incidental thereto, and to file the same, with all exhibits thereto
and all documents in connection therewith, with the Securities and Exchange
Commission and the National Association of Securities Dealers, Inc., granting
unto said attorney-in-fact and agent, full power and authority to do and perform
each and every act and thing requisite and necessary to be done in and about the
premises, as fully to all intents and purposes as the undersigned might or could
do in person, hereby ratifying and confirming all that said attorney-in-fact and
agent, or his substitute or substitutes, may lawfully do or cause to be done by
virtue hereof.

        IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney
this 7th day of March, 1997.

                                        /s/ MARK NOVITCH
                                        ----------------------------
                                            Mark Novitch