1-(3-Trifluoromethylphenyl) piperazine (TFMPP) in the ventral tegmental area reduces the effect of desipramine in the forced swimming test in rats: possible role of serotonin receptors.
1-(3-Trifluoromethylphenyl)piperazine (TFMPP), a serotonin1 (5-HT1) receptor agonist, injected i.p. in doses of 0.1 and 0.6 mg/kg, did not modify the immobility time of rats in the forced swimming test but significantly antagonized the effect of a 7 days treatment with 10 mg/kg per day desipramine (DMI). A similar effect was found on infusing 1 and 5 micrograms/microliters TFMPP bilaterally into the ventral tegmental area (VTA). Infusion of 5 micrograms/microliters TFMPP into the nucleus accumbens or into the globus pallidus did not modify the effect of DMI. The effect of 5 micrograms TFMPP infused into the VTA was prevented by the i.p. administration of 5 mg/kg metergoline, a non-selective serotonin receptor antagonist. Infusion of 5 micrograms/microliters 8-hydroxy-2-(di-n-propylamino)tetralin, a specific 5-HT1A receptor agonist, into the VTA did not modify the effect of DMI. Besides acting as a 5-HT1B receptor agonist, TFMPP may also act on other 5-HT receptor types, but available evidence suggests that its former action is more important. It thus appears that 5-HT1 receptors in the VTA, presumably of the 5-HT1B type, act by preventing the anti-immobility effect of DMI. The role of VTA dopamine and non-dopamine cells in the effect of TFMPP is discussed.
Cervo
L
L
Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
Grignaschi
G
G
Nowakowska
E
E
Samanin
R
R
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000818:Animals; D003863:Depression / Q000378:metabolism*; D003891:Desipramine / Q000037:antagonists & inhibitors*; D007267:Injections; D008297:Male; D008711:Metergoline / Q000494:pharmacology; D010879:Piperazines / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D011985:Receptors, Serotonin / Q000187:drug effects*; D013550:Swimming; D013681:Tegmentum Mesencephali; D013764:Tetrahydronaphthalenes / Q000494:pharmacology
D010879:Piperazines; D011985:Receptors, Serotonin; D013764:Tetrahydronaphthalenes; D008711:Metergoline; C018406:1-(3-trifluoromethylphenyl)piperazine; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D003891:Desipramine