Supersensitivity to d-amphetamine- and apomorphine-induced stereotyped behavior induced by chronic d-amphetamine...

Guinea pigs exhibit an increased sensitivity to both d-amphetamine- and apomorphine-induced stereotyped behavior following chronic pretreatment with d-amphetamine. This chronic agonist or "innervation" supersensitivity is believed to be a reflection of an increased sensitivity of dopamine receptor sites within the corpus striatum to dopaminergic agonists. The appearance of dyskinetic movement disorders in humans following the chronic use of levodopa or amphetamine may be a manifestation of similarly increased dopamine receptor site sensitivity within the striatum. It is suggested that the animal model of "innervation" supersensitivity may be useful in the investigation of these human movement disorders.