Regional displacement by sulpiride of [3H]spiperone binding in vivo. Biochemical and behavioural evidence for a preferential action of limbic and nigral dopamine receptors

The regional displacement by sulpiride of [3H]spiperone binding in vivo was studied in the rat. A low dose of sulpiride (20 mg/kg) displaced [3H]spiperone binding in certain limbic regions (olfactory tubercle, septum) and the substantia nigra but not in the nucleus accumbens or striatum. At this does sulpiride preferentially blocked apomorphine induced apomorphine Higher doses of sulpiride (150 and 250 mg/kg), which blocked apomorphine induced stereotypes and induced catalepsy were found to displace [3H]spiperone binding in all regions studied including the striatum and the nucleus accumbens. Haloperidol (0.1 and 1.0 mg/kg) displaced [3H]spiperone to approximately the same extent in all regions studied.