Amnesia induced by stimulation of the amygdala is attenuated by hexamethonium

Bilateral subseizure stimulation of the amygdala given immediately following training in an inhibitory avoidance task produced retrograde amnesia. Hexamethonium (3.0 and 10.0 mg/kg), a peripherally acting nicotinic cholinergic antagonist, attenuated the retention deficits induced by amygdala stimulation if the drug was given 30 min prior to, but not immediately following training. Hexamethonium had no effect in normal unoperated animals, but did produce a retention deficit in operated control (nonstimulated) animals if it was given immediately following training (3.0 and 10.0 mg/kg). The results suggest that memory deficits induced by electrical stimulation of the amygdala are associated with, or perhaps mediated in some way by peripheral autonomic function.