from SC 13D
1 page
<page> Exhibit 1 Joint Filing Agreement the Undersigned Hereby Agree That the Statement on Schedule 13d Filed by the Undersigned With Respect to the Common Stock of Synaptic Pharmaceutical Corporation Is, and Any Amendment Thereto Signed by Each of the Undersigned Shall Be, Filed on Behalf of Each Undersigned Pursuant to and in Accordance With the Provisions of Rule 13d-1(k) Under the Securities Exchange Act of 1934, as Amended. Dated: August 9, 2001 Warburg Pincus Private Equity VIII, L.P. By: Warburg, Pincus & Co., General Partner By: /S/ Scott Arenare Name: Scott Arenare Title: Attorney in Fact Dated: August 9, 2001 Warburg, Pincus & Co. By: /S/ Scott Arenare Name: Scott Arenare Title: Attorney in Fact Dated: August 9, 2001 Warburg Pincus LLC By: /S/ Scott Arenare Name: Scott Arenare Title: Vice President
