Cholinergic mechanisms in operant responding.

Abstract

To determine the functional significance of acetylcholine (ACh) as a mediator of behavior, operant response levels were investigated in 3 experiments: level of bar pressing differed for 2 strains of rats which differed in brain ACh metabolism; injection of a central cholinergic blocking agent (atropine) resulted in higher rates of bar pressing than injection of a peripheral cholinergic blocking agent (methylatropine); in an open field, Ss injected with atropine were more active than methylatropine or control groups. Results are consistent with the hypothesis that decreased efficiency in central cholinergic neural transmission increases activity level.