The objectives of the proposed research are: (1) to correlate the reported therapeutic and extrapyramidal side effects of phenothiazine and other antipsychotic drugs with their action on acetylcholine metabolism in various regions of the brain; (2) to determine which changes in brain acetylcholine metabolism are related to a direct effect of these drugs on cholinergic neurons which are secondary to the effect of the antipsychotic drugs on dopamine, norepinephrine and serotoninergic receptor sites; and (3) to determine the effect of changes in cyclic AMP metabolism in the striatum on acetylcholine metabolism.