Apomorphine-induced biphasic circling behaviour in 6-hydroxydopamine-lesioned rats. A pharmacological kindling phenomenon.
Factors governing the development of apomorphine-induced biphasic circling behaviour in rats having unilateral 6-hydroxydopamine lesions of the substantia nigra were investigated. It was found that a post-lesion time of at least 2--3 weeks and the repeated exposure to apomorphine were essential for its development. Optimal results were obtained when animals received weekly apomorphine, 0.05 mg/kg sc, in post-lesion weeks 6, 7 and 8. Pretreatment with haloperidol, 1.0 and 2.0 mg/kg ip 1 h beforehand in post-lesion week 9, converted the biphasic response into an enhanced, uniphasic one. The findings suggest that the development of the biphasic response to apomorphine is a multi-factorial process representing a pharmacological kindling phenomenon.
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D005260:Female; D006185:Habituation, Psychophysiologic / Q000187:drug effects; D006220:Haloperidol / Q000494:pharmacology; D006801:Humans; D006892:Hydroxydopamines / Q000494:pharmacology*; D007696:Kindling, Neurologic / Q000187:drug effects*; D016627:Oxidopamine; D051381:Rats; D011919:Rats, Inbred Strains; D013239:Stereotyped Behavior / Q000187:drug effects*; D013997:Time Factors
D006892:Hydroxydopamines; D016627:Oxidopamine; D006220:Haloperidol; D001058:Apomorphine