The effect of anti-parkinsonian drugs on chlorpromazine-induced depression of operant behaviour.

Rats were conditioned in automatic Skinner boxes on a discrete trial avoidance-escape schedule. The chlorpromazine-induced conditioned reflex inhibition could be reversed by apomorphine and amantadine, but not by atropine, trihexyphenidyl and diethazine. These findings seem to provide an additional tool for differentiating the atropine-like and dopaminergic anti-parkinsonian drugs.