Muscarinic receptor blockade attenuates reserpine-mediated Fos induction in the rat striatopallidal pathway

Acute administration of the dopamine-depleting agent reserpine (10 mg/kg) induces Fos expression in striatopallidal neurons of intact rats-an effect that is blocked by pretreatment with the D2 agonist quinpirole (0.5 mg/kg). Systemic administration of the muscarinic antagonist scopolamine (50 mg/kg) partially attenuates reserpine-mediated striatal Fos expression. These data suggest that muscarinic receptors, either within the striatum or in extrastriatal sites, regulate D2 receptor-mediated Fos expression in rat striatopallidal neurons.