R(+)-8-OH-DPAT, a selective 5-HT1A receptor agonist, attenuated amphetamine-induced dopamine synthesis in rat striatum, but not nucleus accumbens or medial prefrontal cortex

R(+)-8-OH-DPAT (0.05, but not 0.025, 0.1, 1 mg/kg), a 5-HT1A receptor agoni st, decreased l-3,4-dihydroxyphenylalanine (DOPA) accumulation in rat stria tum following NSD-1015, an l-aromatic amino acid decarboxylase inhibitor. A mphetamine (1 mg/kg) increased striatal DOPA accumulation, an effect attenu ated by R(+)-8-OH-DPAT (0.05 mg/kg). However, both amphetamine (1 mg/kg) an d R(+)-8-OH-DPAT (0.05 mg/kg) decreased cortical DOPA accumulation; there w ere no additional decreases from their combination. Neither amphetamine (1 mg/kg), R(+)-8-OH-DPAT (0.05 mg/kg), or the combination, significantly affe cted DOPA accumulation in the nucleus accumbens. The significance of and po ssible mechanisms for these findings are discussed. (C) 2000 Elsevier Scien ce B.V. All rights reserved.