Examination of the effects of SCH23390 and raclopride infused in the dorsal striatum on amphetamine-induced timing impulsivity measured on a differential reinforcement of low-rate responding (DRL) task in rats

Abstract Although the striatal dopamine (DA) is reportedly involved in impulsive action, little is known about the DA subtype receptors of dorsal striatum (dSTR) in the impulsive control involved in differential reinforcement of low-rate-responding (DRL) behavior. We examined the receptor-specific dopaminergic modulation of d-amphetamine (AMP)-altered DRL 10 sec (DRL-10 s) performance by locally infusing SCH23390 (SCH) and raclopride (RAC), DA D1 and D2 receptor antagonists, respectively, into the rat’s dSTR. Systemic injection of AMP significantly affected DRL-10 s behavior by increasing total, non-reinforced, and bust responses, as well as by decreasing reinforced responses, which correspondingly caused a leftward shift of the inter-response-time distribution curve as confirmed by a profound decrease in peak time (i.e.,