Effects of the serotonin 5-HT(7) receptor antagonist SB-269970 on the inhibition of dopamine neuronal firing induced by amphetamine.
Using extracellular unitary recordings in anaesthetized rats, this study examined the implication of the serotonin 7 (5-HT(7)) receptors in the inhibitory effect of amphetamine on ventral tegmental area and substantia nigra pars compacta dopamine neuronal activity. The acute administration of the selective 5-HT(7) receptor antagonist, SB-269970 (0.1, 0.5 and 1 mg/kg, i.p.), did not alter the firing activity of dopamine neurons. Interestingly, this antagonist prevented significantly the inhibition of dopamine neuronal firing activity induced by amphetamine (1 mg/kg, i.v.) in the ventral tegmental area, but not in the substantia nigra pars compacta. The present results suggest that 5-HT(7) receptors modulate the dopamine firing activity in the ventral tegmental area, thus affecting preferentially the mesocorticolimbic pathway.
Mnie-Filali
Ouissame
O
Laboratory of Neuropharmacology FRE CNRS 3006, Faculty of Pharmacy, University of Lyon I, 8 avenue Rockefeller, 69373 LYON Cedex 08, France.
Dahan
Lionel
L
Zimmer
Luc
L
Haddjeri
Nasser
N
D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D004298:Dopamine / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D010636:Phenols / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D013378:Substantia Nigra / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D013449:Sulfonamides / Q000494:pharmacology*; D017557:Ventral Tegmental Area / Q000166:cytology / Q000187:drug effects / Q000502:physiology*
D010636:Phenols; D011985:Receptors, Serotonin; C404922:SB 269970; D012702:Serotonin Antagonists; D013449:Sulfonamides; C104425:serotonin 7 receptor; D000661:Amphetamine; D004298:Dopamine