BEHAVIORAL-EFFECTS OF CLOZAPINE - COMPARISON WITH THIORIDAZINE, CHLORPROMAZINE, HALOPERIDOL AND CHLORDIAZEPOXIDE IN SQUIRREL-MONKEYS

  • 1 January 1983
    • journal article
    • research article
    • Vol. 224  (1) , 127-134
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 .mu.mol/kg), chlorpromazine (0.03-2.8 .mu.mol/kg) and haloperidol (0.001-0.08 .mu.mol/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 .mu.mol/kg) and chlordiazepoxide (0.9-167.4 .mu.mol/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. The behavioral effects of clozapine differed qualitatively from those of representative antipsychotic and antianxiety drugs.