title: Behavioral effects of clozapine: comparison with thioridazine, chlorpromazine, haloperidol and chlordiazepoxide in squirrel monkeys.
abstract: The behavioral effects of the antipsychotic drug, clozapine, were compared with those of thioridazine, chlorpromazine, haloperidol and chlordiazepoxide. Behavior of squirrel monkeys was controlled by different consequences of a lever-pressing response (presentation of food, presentation of electric shock or termination of a stimulus associated with electric shock) under different schedules of reinforcement (a fixed-interval schedule or a multiple schedule with alternating fixed-ratio and fixed-interval components). The effects of thioridazine (0.2-24.6 mumol/kg), chlorpromazine (0.03-2.8 mumol/kg) and haloperidol (0.001-0.08 mumol/kg) were largely independent of the type of schedule or the type of consequent event that maintained responding: each drug produced dose-related decreases in responding under all conditions in which they were studied. Clozapine (0.1-9.2 mumol/kg) and chlordiazepoxide (0.9-167.4 mumol/kg) also only decreased responding under most schedule conditions; however, intermediate doses of either drug markedly increased responding maintained by presentation of food under the fixed-interval schedule (whether programmed singly or as a component of the multiple schedule). Only clozapine increased responding maintained by presentation of electric shock under the fixed-interval schedule. Thus, the behavioral effects of clozapine differed qualitatively from those of representative antipsychotic and antianxiety drugs.
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002707:Chlordiazepoxide / Q000494:pharmacology; D002746:Chlorpromazine / Q000494:pharmacology; D003024:Clozapine / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects; D003984:Dibenzazepines / Q000494:pharmacology*; D004597:Electroshock; D005502:Food; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D012055:Reinforcement Schedule; D012453:Saimiri; D013881:Thioridazine / Q000494:pharmacology; D014149:Tranquilizing Agents / Q000494:pharmacology*
chemical_list: D003984:Dibenzazepines; D014149:Tranquilizing Agents; D002707:Chlordiazepoxide; D003024:Clozapine; D006220:Haloperidol; D013881:Thioridazine; D002746:Chlorpromazine