EFFECTS OF ELECTRICAL-STIMULATION OF THE AMYGDALOID CENTRAL NUCLEUS ON NEOCORTICAL AROUSAL IN THE RABBIT

This study sought to determine whether electrical stimulation of the amygdaloid central nucleus (ACe) produces cholinergically mediated neocortical arousal manifested in the suppression of frontal cortex delta wave (1-4 Hz) activity. Stimulation in both anesthetized and conscious rabbits produced a suppression of delta activity that was accompanied by bradycardia and blocked by cholinergic antagonists. Stimulation of the adjacent putamen did not produce delta suppression, whereas stimulation of the adjacent ventral globus pallidus produced a suppression of shorter duration than that produced by ACe stimulation. The results suggest that the ACe influences neocortical arousal, which may be mediated by its influence on the activity of cholinergic neurons of the nucleus basalis.