Quinpirole attenuates the striatal fos expression induced by escape behavior

Several studies have shown that the D2-like dopamine receptor agonist quinpirole is able to markedly potentiate the striatal Fos expression induced by D1 agonists. The present study examined the effects of quinpirole on the striatal Fos-like immunoreactivity (FLI) induced by escape behavior. Male rats were pretreated with either saline or quinpirole (0.156, 0.625, 1.25 or 2.5 mg/kg) and 30 min later, placed in a shuttle box and required to crossover every 30 s in order to escape mild footshock. Animals were sacrificed 30 min following the completion of a 1-h block of escape trials and sections through the striatum were processed for FLI. Pretreatment with quinpirole produced a marked, dose-dependent, attenuation of escape-induced FLI in the striatum. These findings demonstrate that quinpirole affects the striatal Fos expression induced by shuttling in a very different fashion than it does that induced by D1 agonists, and further support the view that dopaminergic mechanisms play an important role in behaviorally induced striatal Fos expression.