Behavioral effects of cholinergic stimulation of the thalamic reticular formation.

Abstract

Cholinergic stimulation of thalamic midline nuclei of rats reliably retarded acquisition of a shuttle-box avoidance response without affecting asymptotic performance. Cholinergic stimulation of reticular nuclei significantly depressed asymptotic performance as well as acquisition rate. Acquisition and performance of instrumental escape responses were unimpaired. Cholinergic stimulation of both midline and reticular nuclei (a) reduced exploratory behavior; (b) impaired performance of previously acquired bar-pressing responses for food; and (c) failed to affect food and water intake of deprived Ss. Local applications of the cholinergic blocking agent atropine (a) increased locomotor activity, (b) depressed responding rate for food and (c) failed to affect food or water intake. Control tests suggest that effects may be specific to cholinergic stimulation or blockade.