Effects of apomorphine and haloperidol on "spontaneous" sterotyped licking behavior in the Cebus monkey

Three recently arrived drug naive Cebus apella monkeys with "spontaneous" stereotyped oral movements were trated with apomorphine and haloperidol using a wide dose range. Low doses of apomorphine suppressed the oral stereotypies without affecting normal behaviour such as grooming and scratching. Higher doses of apomorphine and haloperidol also decreased or abolished the oral stereotypies, but induced generalized stereotypies (apomorphine) or dynstonia/parkinsonism (haloperidol), suppressing normal behaviour. The findings indicate that dopamine is involved in these presumably stress-induced (not drug-induced) stereotypies.