Altered response to apomorphine and haloperidol after nine days of cocaine injections.

Sprague Dawley rats, pretreated with nine daily injections of 20 mg/Kg cocaine or saline, were evaluated for aspects of their behavioral response to apomorphine, haloperidol, or cocaine, twenty-four hours after their last pretreatment injection. Data obtained from saline and cocaine pretreated animals indicated that: cocaine pretreated rats were more sensitive to haloperidol-induced catalepsy, less responsive to some of the stereotypic effects of apomorphine and similar in their responses to the anticataleptic properties of cocaine.