Serotonin-1B receptors in the ventral tegmental area modulate cocaine-induced increases in nucleus accumbens dopamine

Previous work has demonstrated that peripheral serotonin1B (5-HT1B) receptor agonist administration facilitates the behav-ioral and neurochemical effects of cocaine. This study used dual probe microdialysis to investigate whether activation of serotonin1B (5-HT1B) receptors in the ventral tegmental area (VTA) alters the ability of peripherally administered cocaine to elevate dopamine (DA) levels in the ipsilateral nucleus accum-bens (NAcc) of drug-naive Wistar rats. Intra-VTA administration of the selective 5-HT1B agonist 1,4-dihydro-3-(1,2,3,6-tetrahy-dro-4-pyridinyl)-5H-pyrrolo [3,2-b]pyridin-5-one dihydrochlor-ide (CP 93,129) by reverse dialysis produced a dose-dependent (30 and 100 M) potentiation of cocaine-induced (10 mg/kg i.p.) increases in NAcc DA efflux and concurrent cocaine-in-duced decreases in VTA GABA efflux. There was no effect o