R(-8-OH-DPAT, A 5-HT1A RECEPTOR AGONIST, INHIBITS AMPHETAMINE-INDUCEDDOPAMINE RELEASE IN RAT STRIATUM AND NUCLEUS-ACCUMBENS())

Systemic administration of R(+)-8-OH-DPAT (8-hydroxy-2-(di-n-propylami no)tetralin) a selective serotonin (5-hydroxytryptamine, 5-HT)(1A) rec eptor agonist (25, 50, and 100 mu g/kg s.c.), administered 30 min prio r to d-amphetamine, significantly inhibited the d-amphetamine sulfate (1.0 mg/kg s.c.)-induced increase in extracellular dopamine levels in the striatum and nucleus accumbens of freely moving rats, as determine d by in vivo microdialysis. The ability of R(+)-8-OH-DPAT (50 mu g/kg s.c.) to inhibit d-amphetamine sulfate (1.0 mg/kg s.c.)-induced increa se in extracellular dopamine levels was abolished by WAY 100,635 ethox yphenyl)-1-piperazinyl]ethyl]-n-(2-pyridinyl) cyclohexanecarboxamide t rihydrochloride), a selective 5-HT1A receptor antagonist (100 mu g/kg s.c.), administered 5 min prior to R(+)-8-OH-DPAT in both regions. The se results indicate that the 5-HT1A receptor may exert an inhibitory e ffect on amphetamine-induced dopamine release.