Neurophysiological consequences of combined cholinergic and noradrenergic lesions.

The present study investigates the effects of an anti-cholinesterase, tetrahydroaminoacridine (THA), on combined nucleus basalis (NB, quisqualic acid) and dorsal noradrenergic bundle (DNB, 60HDA) lesion-induced high-voltage spindle (HVS) activity. THA at 3 mg/kg, but not at 1 mg/kg, decreased HVS activity in NB- and DNB-lesioned rats. HVS activity in NB- and DNB-lesioned rats treated with THA at 6 mg/kg was lower than in saline-treated controls. In NB-lesioned rats subjected to an additional DNB lesioning, the HVS suppressing effect of THA at 3 mg/kg was decreased. The present results suggest that NB cholinergic and DNB noradrenergic systems interact in the regulation of HVS activity and that the efficacy of an anticholinesterase drug (THA) in reversing NB cholinergic lesion-induced thalamocortical activation deficit is decreased by combined DNB noradrenergic lesion.