Phencyclidine-induced stereotyped behavior in rats: dose response effects and antagonism by neuroleptics.

Phencyclidine hydrochloride produced a very characteristic and reproducible stereotyped behavioral syndrome in rats. Both the intensity and the duration of the phencyclidine-induced stereotyped behavior are elicited in a dose-dependent manner in the 2–16 mg/kg dose range. The predominant behavior elicited by low doses was repetitive lateral head swaying, while with higher doses circling and backward walking were observed in addition to the head swaying. This behavior was antagonized by the neuroleptic agents chlorpromazine, haloperidol, and pimozide, but not by α- or β-adrenergic blockers. These results indicate that the phencyclidine-induced stereotyped behavior may be mediated by central dopaminergic mechanisms.