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                                                                    Exhibit 10.3
                                                                  EXECUTION COPY

                               SECURITY AGREEMENT

            THIS SECURITY AGREEMENT is made as of August 13, 2003, by and
between NEUROLOGIX, INC., a Delaware corporation (the "Corporation"), and CHANGE
TECHNOLOGY PARTNERS, INC., a Delaware corporation (the "Secured Party").

            WHEREAS, the Secured Party, CTP/N Merger Corp. and the Corporation
are parties to that certain Agreement and Plan of Merger dated the date hereof
(the "Merger Agreement");

            WHEREAS, in connection with the Merger Agreement, the Corporation
has issued a Senior Secured Promissory Note, dated as of the date hereof, in the
aggregate principal amount of $750,000, in favor of the Secured Party (the
"Note"); and

            WHEREAS, it is the intention of the parties hereto that the granting
of the security interest pursuant to this Security Agreement will secure all of
the obligations of the Corporation under the Note, including without limitation,
the payment of fees and expenses in the event of an Event of Default (such
obligations being referred to herein as the "Secured Obligations").

            NOW, THEREFORE, in consideration of the foregoing and the mutual
agreements and covenants herein contained, and intending to be legally bound
hereby, the parties hereto hereby agree as follows:

            1. The Corporation hereby grants to the Secured Party a security
interest in the Collateral (as defined in paragraph 2 below), to secure the
Secured Obligations.

            2. (a) The collateral (collectively, the "Collateral") shall be all
assets of the Corporation whether now owned or hereafter acquired and all
proceeds therefrom including, but not limited to, the following:

                        (i) any machinery, equipment, furniture, fixtures,
inventory or work-in-progress;

                        (ii) cash and cash equivalents;

                        (iii) accounts receivable;

                        (iv) contracts, leases, software, source and operating
codes, designs or marketing and other plans;

                        (v) all patents and patent applications to which the
Corporation acquires any right, title or interest in or to, including without
limitation, the
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inventions and improvements described and/or claimed therein, together with any
reissues, divisions, continuations, renewals, extensions, and continuations in
part thereof and any United States and foreign patents that may issue thereon
for the United States and all other countries ("Patents");

                        (vi) all agreements, whether written or oral, providing
for the grant to or by the Corporation of any right to manufacture, use or sell
any invention covered by a Patent, including without limitation, the patent
license agreement between the Corporation and Rockefeller University, except to
the extent that such grant of a security interest or assignment (a) is
prohibited under any licensing agreement currently in effect and (b) such grant
of a security interest or assignment would result in a breach of such licensing
agreement that would allow termination of such licensing agreement ("Patent
Licenses");

                        (vii) all proceeds and products of each Patent and
Patent License, including without limitation, all income, royalties, damages and
payments now or hereafter due and/or payable with respect to any Patent or
Patent License, including damages and payments for past or future infringements
thereof, the right to sue for past, present and future infringements thereof,
and all rights corresponding hereto throughout the world;

                        (viii) all of Corporation's trademarks, trade names,
corporate names, company names, business names, fictitious business names, trade
styles, trade dress and other designations, service marks, logos, other source
or business identifiers, prints and labels on which any of the foregoing have
appeared or appear, designs and general intangibles of like nature, now existing
or hereafter adopted or acquired, all registrations and recordings thereof, and
all applications in connection therewith, including, without limitation,
registrations, recordings, and applications in the Patent and Trademark Office
or in any similar office or agency of the United States, any State thereof or
any other country or any political subdivision thereof, and all reissues,
extensions or renewals thereof ("Trademarks");

                        (ix) all agreements, whether written or oral, now or
hereafter in existence, providing for the grant to or by the Corporation of any
right to use any Trademark, except to the extent that such grant of a security
interest or assignment (a) is prohibited under any licensing agreement currently
in effect and (b) such grant of a security interest or assignment would result
in a breach of such licensing agreement that would allow termination of such
licensing agreement ("Trademark Licenses") ;

                        (x) all of the goodwill of the Corporation's business
connected with the use of, and symbolized by, each Trademark and Trademark
License;

                        (xi) all products and proceeds of each Trademark and
Trademark License, including, without limitation, any claim by the Corporation
against third parties for past, present or future infringement or dilution of
any Trademark, or for injury to the goodwill associated with any Trademark;
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                        (xii) all general intangibles, as defined in the Uniform
Commercial Code (or other applicable state laws) of each jurisdiction where any
of the Collateral is located, and whether or not so included in such definition,
all intangible assets of whatever kind or nature of Corporation, whether now
owned or hereafter acquired, including, without limitation, all copyrights,
copyright applications, all franchises, licenses, permits, all good will
associated with Corporation's business, customer lists, proprietary rights and
know-how, trade secrets, choses in action and rights to indemnity; and

                        (xiii) all products and proceeds of any and all of the
foregoing.

                  (b) If, before the Secured Obligations shall have been
satisfied in full, the Corporation shall (i) obtain rights in or to any
additional Patents or patentable inventions, or become entitled to the benefit
of any Patent for any reissue, division, continuation, renewal, extension, or
continuation-in-part of any Patent or any improvement on any such Patent, (ii)
obtain rights in or to any additional Trademarks, or (iii) obtain rights in or
to any other assets that would have been Collateral had they been held as of the
date hereof, the provisions of this Security Agreement shall automatically apply
thereto and the Corporation shall give to the Secured Party written notice
thereof within five (5) days after the end of each fiscal quarter.

                  (c) The Corporation agrees to do such further acts and things,
and to execute and deliver such additional conveyances, assignments, agreements
and instruments, as Secured Party may at any time reasonably request in
connection with the administration or enforcement of this Security Agreement or
related to the Collateral, or any part thereof or in order better to assure and
confirm unto Secured Party its rights, powers and remedies hereunder.

            3. The occurrence of any one or more of the following events shall
constitute an event of default ("Default") by the Corporation under this
Security Agreement if not cured within fifteen (15) days after written notice
thereof from the Secured Party: (a) an Event of Default under the Note; (b) in
the event of substantial loss, theft or destruction of, or substantial damage
to, the Collateral not adequately covered by insurance, or the making or filing
of any lien, levy, or execution on, or seizure, attachment or garnishment of, a
substantial portion of the Collateral not discharged, bonded, paid or removed
within sixty (60) days; (c) if the Corporation shall be liquidated, dissolved,
or shall fail to maintain its corporate existence in good standing; (d) if there
shall be filed by or against the Corporation any petition for any relief under
the bankruptcy laws of the United States now or hereafter in effect or under any
insolvency, readjustment of debt, dissolution or liquidation law or statute of
any jurisdiction now or hereafter in effect (in the case of any filing against
the Corporation, which is not discharged, vacated or dismissed within sixty (60)
days); or (e) if the usual business of the Corporation shall be terminated or
suspended for more than sixty (60) days.
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            4. Upon the occurrence of any Event of Default under the Note and
the expiration of all applicable cure periods, if any, or of any Default
hereunder not cured by the Corporation or its affiliates within fifteen (15)
days after written notice thereof from the Secured Party, the Secured Party
shall have all rights and remedies of a secured party under the laws of the
State of New York, including the Uniform Commercial Code of the State of New
York (the "UCC").

            5. It is expressly agreed by all parties hereto that the Secured
Obligations of the Corporation under, and with respect to, the Note shall not be
subject to any set-offs, defenses or counterclaims which the Corporation or its
affiliates may have against the Secured Party under, or arising out of, the
Note.

            6. Any notices or demands to be effective under this Security
Agreement shall be given pursuant to the notice provisions of the Note.

            7. The proceeds of the sale of any of the Collateral by the Secured
Party pursuant to the terms hereof after a Default shall be applied as follows:

                  FIRST : To the payment of the costs and expenses of such sale,
including the out-of-pocket expenses of the Secured Party and the reasonable
fees and out-of-pocket expenses of counsel employed by the Secured Party in
connection therewith;

                  SECOND : To the payment of all amounts then owing to the
Secured Party under the Secured Obligations;

                  THIRD : The balance (if any) of the proceeds shall be paid to
the Corporation or its successors or assigns.

            8. The Corporation hereby represents, warrants and agrees that:

                  (a) The execution, delivery and performance of this Security
Agreement are within its powers, corporate or otherwise, have been duly
authorized by all required action and do not and will not contravene any law or
any agreement or undertaking to which it is a party or by which it may in any
way be bound or its certificate of incorporation or by-laws;

                  (b) Except for any liens granted to (i) the Secured Party
pursuant to this Security Agreement, and (ii) Palisade Private Partnership, L.P.
pursuant to the Credit Line Agreement, dated as of November 1, 1999, by and
between the Corporation and Palisade Private Partnership, L.P., (A) the
Corporation is the owner of the Collateral and (B) all such Collateral is owned
free and clear of any and all liens.

                  (c) Appropriate UCC-1 financing statements evidencing the
Secured Party's security interest hereunder have been or are concurrently
herewith being filed by the Corporation in the State of Delaware, and upon such
filing (which all such filings and other related documents, have been or are
concurrently being delivered to the Secured Party in completed and executed
form), the security interest granted pursuant to
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this Security Agreement shall constitute a valid and continuing perfected
security interest in favor of the Secured Party, in the Collateral for which
perfection is governed by the UCC. Such security interest will be prior to all
other liens on the Collateral.

                  (d) The exact legal name of the Corporation is as set forth on
page one hereof. The Corporation has no trade names, fictitious names or other
names except its legal name, and does not operate in any jurisdiction under, and
has not had or operated in any jurisdiction within the four-year period
preceding the date hereof under, any trade name, fictitious name or other name
other than its legal name.

            9. As long as any of the Secured Obligations remain outstanding, the
Corporation covenants and agrees that:

                  (a) It will execute and file, UCC-1 financing statements
evidencing the security interest granted to the Secured Party hereunder, and any
additional documents necessary to perfect a security interest in the Collateral;

                  (b) Upon the written request of the Secured Party, it will
take all reasonably necessary action requested by the Secured Party to perfect,
continue, evidence, preserve, protect or validate the security interest of and
assignment and pledge to the Secured Party hereunder or to enable the Secured
Party to exercise and enforce its rights hereunder, including, but not limited
to, (i) executing and delivering one or more notices, statements, agreements or
other writings, and (ii) delivering to the Secured Party, endorsed or
accompanied by such instruments of assignment as the Secured Party may
reasonably require, and stamping or otherwise marking, in such manner as the
Secured Party may reasonably require, any and all chattel paper, instruments,
letters and advices of credit and documents;

                  (c) It shall: (i) be the sole owner of each and every item of
Collateral, (ii) defend the Collateral against the claims and demands of all
persons, (iii) in the case of tangible property constituting part of the
Collateral, properly maintain and keep in good order and repair such property;

                  (d) With respect to its properties, assets and business, it
shall maintain insurance against loss or damage, to the extent that property,
assets and businesses of similar character are usually so insured by companies
similarly situated and operating like properties, assets or businesses with
responsible insurance companies reasonably satisfactory to the Secured Party,
said insurance to indicate the Secured Party as an additional insured;

                  (e) It shall comply with the requirements of all leases,
mortgages and other instruments relating to premises where any Collateral is
located;

                  (f) Except in the ordinary course of business consistent with
past practice, it shall not sell or otherwise dispose of (i) any of its
accounts, except for purposes of collection, (ii) any of its inventory, or (iii)
any of its equipment, except equipment no longer useful in the operation of the
Corporation's business;
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                  (g) It shall immediately give notice to the Secured Party of
(i) any change in (A) its name, identity or corporate structure, (B) its state
of incorporation or the location of its chief executive office or any other
place of business, or (C) the location of its books and records concerning any
of the Collateral, (ii) the location of each new place of business opened by the
Corporation, and (iii) and any substantial loss or depreciation in the value of
any of the Collateral, and will provide the Secured Party with such other
information as to the Collateral as the Secured Party may request;

                  (h) It shall immediately give notice to the Secured Party that
an Event of Default, as defined in the Note, has occurred or that an event
which, with the giving of notice or lapse of time, or both, would constitute a
Default, has occurred and specifying the action which the Corporation has taken
and proposes to take with respect thereto;

                  (i) It shall conduct its operations only in the ordinary
course of business consistent with past practice (except for the transactions
contemplated by the Merger Agreement); and

                  (j) It shall comply with all statutes, rules and regulations
and duly pay and discharge all taxes or other claims which might become a lien
upon any of its properties, except to the extent that such items are being in
good faith appropriately contested.

                  (k) It shall use reasonable commercial efforts to keep in full
force and effect all material rights, franchises, intellectual property rights
and goodwill relating to or pertaining to its business, consistent with past
practice.

            10. Without the consent of the Secured Party, the Corporation shall
not:

                  (a) Create, incur, assume or suffer to exist any liability for
borrowed money, except (i) purchase money indebtedness for the purchase of new
equipment (but not for the refinancing of any collateral securing this loan);
(ii) indebtedness to the Secured Party contemplated by the Note; (iii) other
indebtedness for borrowed money (whether or not constituting a refinancing of
existing indebtedness) so long as (x) such indebtedness is not secured by
collateral securing repayment of this loan and (y) the incurrence of which will
not cause an Event of Default, or an event which with notice or the lapse of
time or both would constitute an Event of Default, hereunder;

                  (b) Create, incur, assume or suffer to exist any security
interest, mortgage, pledge, lien, charge or other encumbrance of any nature
whatsoever, except: (i) liens securing purchase money indebtedness for the
purchase of new equipment (but not for the refinancing of any collateral
securing this loan); (ii) liens and security interests of Secured Party; (iii)
liens securing the payment of taxes, either not yet overdue or the validity of
which are being contested in good faith by appropriate proceedings diligently
pursued and available to Corporation and with respect to which adequate reserves
have
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been set aside on its books; (iv) nonconsensual statutory liens (other than
liens securing the payment of taxes) arising in the ordinary course of
Corporation's business to the extent: (x) such liens secure indebtedness which
is not overdue or (y) such liens secure indebtedness relating to claims or
liabilities which are fully insured and being defended at the sole cost and
expense and at the sole risk of the insurer or being contested in good faith by
appropriate proceedings diligently pursued and available to Corporation, in each
case prior to the commencement of foreclosure or other similar proceedings and
with respect to which adequate reserves have been set aside on its books; and
(iv) the security interests and liens created hereunder;

                  (c) Assume, endorse, be or become liable for or guarantee the
obligations of any other person except by the endorsement of negotiable
instruments for deposit or collection in the ordinary course of business;

                  (d) Lend or advance money, credit or property to or invest in
(by capital contribution, loan, purchase or otherwise) any firm, corporation, or
other person except (i) investments in United States Government obligations and
certificates of deposit of any bank institution with combined capital and
surplus of at least $200,000,000, (ii) trade credit, or (iii) security deposits;

                  (e) Make, declare or pay any dividend or distribution on, or,
directly or indirectly, redeem, purchase or otherwise acquire, any shares of its
capital stock or any securities convertible or exchangeable into or exercisable
for any shares of the Corporation's capital stock, except to the extent
necessary to satisfy its obligation pursuant to Section 262 of the Delaware
General Corporation Law as set forth in the Merger Agreement; or

                  (f) Enter into any transaction, agreement, arrangement or
understanding between the Corporation, on the one hand, and any officer,
director, employee, family member of any of the foregoing, or any Affiliate
(including, without limitation, Palisade Capital Management LLC and its
Affiliates) of the Corporation or other persons, on the other hand, except (i)
in the ordinary course of business consistent with past practice, or (ii) as
contemplated by the Merger Agreement. For purposes of this Security Agreement,
"Affiliate" means, with respect to any entity, any person, corporation or other
entity which controls, is controlled by, or is under common control with, such
person, corporation or other entity. For the purposes of this definition,
"control" (including, with correlative meanings, the terms "controlling,"
"controlled by" and "under common control with"), as applied to any person,
corporation or other entity means the possession, directly or indirectly, of the
power to direct or cause the direction of the management and policies of that
person, corporation or other entity whether through the ownership of voting
securities, by contract or otherwise.

            11. The Corporation's agreements and duties hereunder shall be
performed by it at its sole cost and expense. If the Corporation shall fail to
do any act or thing which it has covenanted to do hereunder, the Secured Party
may (but shall not be obligated to) do the same or cause it to be done, either
in its name or in the name and on
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behalf of the Corporation and the Corporation hereby irrevocably authorizes the
Secured Party so to act.

            12. The Corporation covenants and agrees that it shall indemnify,
defend, protect and hold the Secured Party, its directors, officers, employees,
members, owners, managers, fiduciaries and agents, at all times, harmless from
and against any and all claims, damages, actions, suits, proceedings,
investigations, losses, obligations, fines, liabilities, judgments, demands,
assessments, adjustments, costs and expenses (including specifically, but
without limitation, reasonable attorneys' fees and expenses of investigation)
and amounts paid in settlement of any pending or threatened or completed claim,
action, suit, proceeding or investigation as a result of or arising from or are
related to any nonfulfillment in any material respect of any agreement on the
part of the Corporation set forth in the Note or this Security Agreement.

            13. Subject to the terms and conditions herein provided, each of the
parties hereto shall use its best efforts to take, or cause to be taken, all
action, and to do, or cause to be done, all things reasonably necessary, proper
or advisable under applicable laws and regulations to consummate and make
effective the transactions contemplated hereby. In the event that at any time
after this Security Agreement has become effective, any further action is
necessary to carry out its purposes, the Secured Party, the Corporation or the
proper directors or officers of either, as the case may be, shall take all such
action without any further consideration therefor.

            14. This Security Agreement shall continue in full force and effect
until all Secured Obligations then outstanding shall have been paid in full and
all rights of the Secured Party hereunder shall have been satisfied or other
arrangements for the securing of such rights satisfactory to the Secured Party
shall have been made. Upon the irrevocable payment in full in cash of the
Secured Obligations by the Corporation, the Secured Party shall forthwith
deliver to the Corporation UCC-3 termination statements, terminating the Secured
Party's security interest hereunder and the security interest granted by this
Security Agreement shall become null and void and of no further force and
effect.

            15.   (a) All terms used herein shall have the meanings as defined
in the UCC, unless the context otherwise requires.

                  (b) No provision hereof shall be modified, altered or limited
except by a written instrument expressly referring to this Security Agreement
and to such provision, and executed by the party to be charged.

                  (c) This Security Agreement shall be binding upon and inure to
the benefit of the successors or assigns of the Secured Party and the
Corporation.

                  (d) THIS SECURITY AGREEMENT SHALL BE GOVERNED AND CONSTRUED IN
ACCORDANCE WITH BY THE INTERNAL LAWS OF THE STATE OF NEW YORK WITHOUT REGARD TO
THE PRINCIPLES OF CONFLICTS OF LAWS THEREOF.

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                  (e) This agreement may be executed in one or more
counterparts, and by the different parties hereto in separate counterparts, each
of which when executed shall be deemed to be an original but all of which taken
together shall constitute one and the same agreement.

                     [Remainder of Page Intentionally Blank]
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            IN WITNESS WHEREOF, the undersigned have executed or caused this
Security Agreement to be executed on the date first set forth above.

                                        NEUROLOGIX, INC.


                                        By: /s/ Martin J. Kaplitt
                                           -------------------------------------
                                            Name:  Martin J. Kaplitt
                                            Title: President

                                        CHANGE TECHNOLOGY PARTNERS, INC.


                                        By: /s/ Michael Gleason
                                           -------------------------------------
                                            Name:  Michael Gleason
                                            Title: Chairman and Chief
                                                   Executive Officer