Differentiation of nicotinic and muscarinic anticholinergic effects on two schedules of reinforcement

An examination was made of the differential effects of the anticholinergic compounds, scopolamine and mecamylamine, on response inhibition under two different reinforcement schedules. Rats were trained on a multiple-schedule DRL-DRO. Each subject was then run under each of six different drug-dose combinations. All dose levels of both scopolamine and mecamylamine had significant disruptive effects on responding during the DRO schedule when compared to control injections of saline. Only high dose levels of scopolamine tended to disrupt responding during the DRL schedule. The peripheral action of methyl scopolamine and hexamethonium, on the other hand, had no measurable effect.