TFMPP may produce its stimulus effects via a 5-HT1B mechanism.

Tests of stimulus generalization were conducted using rats trained to discriminate 1.0 mg/kg of 1-(3-trifluoromethylphenyl)piperazine (TFMPP) from saline in a standard two-lever operant procedure. Generalization of the TFMPP-stimulus was found to occur with fenfluramine and 1-(3-chlorophenyl)-piperazine (mCPP); generalization did not occur with 8-OH DPAT, quipazine, LSD, 5-OMe DMT or 2,5-DMA. Furthermore, the TFMPP-stimulus was not antagonized by pretreatment of the animals with tetrahydrotrazodone (THT). Based on the results of these studies, and on the results of previous binding studies with these same agents, it is suggested that the stimulus properties of TFMPP are mediated primarily via a 5-HT1B mechanism.