THE EFFECTS OF HALOPERIDOL AND CLOZAPINE ON PCP-INDUCED AND AMPHETAMINE-INDUCED SUPPRESSION OF SOCIAL-BEHAVIOR IN THE RAT

Previous work has shown that phencyclidine (PCP) and amphetamine decre ase social behavior in rats. The purpose of the present study was to d etermine the effects of the dopamine antagonists clozapine and haloper idol on PCP- and amphetamine-induced changes in rat social behavior. A n intruder paradigm was used, in which rats were injected with drug an d placed into a stable home colony of three other rats. Social behavio rs were recorded for 30 min. Both amphetamine (4.0 mg/kg) and PCP (4.0 mg/kg) substantially reduced social behavior. Haloperidol and clozapi ne did not produce a general reversal of the effects of amphetamine or PCP on the total number of social behaviors. Nevertheless, 0.025 mg/k g haloperidol did reverse the effects of PCP and amphetamine on some o f the specific social behaviors observed (side threats, mounting, craw ling under). Clozapine had no effect on reversing the actions of amphe tamine on social behavior, but 2.0 mg/kg clozapine did reverse the eff ect of PCP on side threats and mounting. These results indicate that D A antagonists do not restore normal social behavior in animals treated with PCP or amphetamine, but can reverse some of the effects of PCP o r amphetamine on specific social behaviors.