The comparative roles of dopaminergic and serotonergic mechanisms in mediating quipazine induced locomotor activity

Summary Quipazine maleate (50–100g) injected bilaterally into the nucleus accumbens septi (NAS) of unpretreated rats produced a marked dose-dependent rise in locomotor activity (LA) that was nearly devoid of the stereotypies seen after the systemic or intrastriatal administration of this piperazine derivative. Injection of a low dose of the dopamine blocking agent haloperidol resulted in a marked antagonism of the LA elicited by quipazine (50g) in the NAS; but methysergide, a central serotonin antagonist, was without effect. These results indicate that quipazine induced LA is mediated, at least partially, by DA receptors situated in the NAS, and that serotonin receptors do not play a significant role in this behavior.