Behavioral effects of chronic phencyclidine in monkeys

PHENCYCLIDINE (PCP) and other NMDA receptor antagonists such as ketamine in duce psychotic symptoms that are difficult to reverse with current medicati ons and which closely resemble those of schizophrenia. This study investiga ted the behavioral effects of continuous PCP administration in six socially -housed Cebus apella monkeys. Chronic treatment was associated with a susta ined decrease in stereotyped locomotion (pacing) and a sustained increase i n scanning behavior. Treatment was also associated with a modest decrease i n self- and environment-directed behavior and goal-directed locomotion and an increase in affiliative behavior at lower doses. Four animals had one or more episodes of extreme motoric and physiological responses precipitated by stressful events. The results indicate that behavioral effects of chroni c PCP in primates differ from those seen following acute treatments and rep resent an appropriate model system for new antipsychotic drug development. (C) 1999 Lippincott Williams & Wilkins.