EFFECTS OF SOME CHOLINERGIC AGONISTS ON NEOCORTICAL SLOW-WAVE ACTIVITY IN RATS WITH BASAL FOREBRAIN LESIONS

Chronic rats, prepared with unilateral injections of kainic acid in the left basal forebrain, displayed prominent large amplitude slow wave activity in the neocortex ipsilateral to the injection. Oxotremorine and pilocarpine, given systemically following pretreatment with methyl scopolamine to block peripheral muscarinic effects, restored low voltage fast activity (LVFA) in a dose-related manner. Oxotremorine was more potent than pilocarpine. Arecoline was not consistently effective. Tetrahydroaminoacridine abolished abnormal 4-6 Hz rhythmical slow waves in the left neocortex but had little effect on large amplitude irregular slow waves. Direct-acting cholinergic agonists can restore near-normal neocortical activity after extensive cholinergic deafferentation of the neocortex.