Chronic scopolamine-injection-induced cognitive deficit on reward-directed instrumental learning in rat is associated with CREB signaling activity in the cerebral cortex and dorsal hippocampus

Rationale Scopolamine, a nonselective muscarinic receptor antagonist, has been used in experimental animal models of dementia. It has been demonstrated to disrupt performances in a battery of behavioral tests. However, no attempt has been made to determine how scopolamine-treated animals would respond to a series of reward-directed instrumental learning (RDIL) tasks.