CHRONIC PHENYLETHYLAMINE STEREOTYPY IN RATS - NEW ANIMAL-MODEL FOR SCHIZOPHRENIA

The chronic administration of phenylethylamine (50 mg/kg) or d-amphetamine (3.75 mg/kg) produced stereotyped behavior in rats. This chronic administration induced a behavioral sensitization consisting of an increase in intensity of stereotypes and a decrease in their latency to onset. The substitution of phenylethylamine for d-amphetamine or vice versa maintained stereotypes and the sensitization effect. Acute pretreatments with the antipsychotic dopamine blockers haloperidol and pimozide blocked stereotypy induced by phenylethylamine and d-amphetamine; antipsychotics with fewer extrapyramidal effects, thioridazine and clozapine, preferentially blocked pehnylethylamine-evoked behavior. Since stereotypy induced by phenylethylamine, unlike that induced d-amphetamine, did not depend so greatly upon neostriatal actions suggested that it may represent a better animal model for schizophrenia.