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

Eur J Pharmacol. 1989 Nov 14;171(1):119-25. doi: 10.1016/0014-2999(89)90435-4.

Abstract

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.

MeSH terms

  • 8-Hydroxy-2-(di-n-propylamino)tetralin
  • Animals
  • Depression / metabolism*
  • Desipramine / antagonists & inhibitors*
  • Injections
  • Male
  • Metergoline / pharmacology
  • Piperazines / administration & dosage
  • Piperazines / pharmacology*
  • Rats
  • Receptors, Serotonin / drug effects*
  • Swimming
  • Tegmentum Mesencephali
  • Tetrahydronaphthalenes / pharmacology

Substances

  • Piperazines
  • Receptors, Serotonin
  • Tetrahydronaphthalenes
  • Metergoline
  • 1-(3-trifluoromethylphenyl)piperazine
  • 8-Hydroxy-2-(di-n-propylamino)tetralin
  • Desipramine