Time schedule of apomorphine administration determines the degree of globus pallidus excitation.
Intravenous administration of a single 320 microgram/kg bolus dose of apomorphine significantly increased in unit activity of rat globus pallidus neurons. Significantly attenuated responses to apomorphine were observed when 320 microgram/kg apomorphine was administered i.v. in divided doses (5, 35, 280 microgram/kg) 3-5 min apart or when 320 microgram/kg apomorphine was given i.v. 8 min after a nonexcitatory 'priming' dose (20 microgram/kg i.v.) of apomorphine. These results suggest that the expression and magnitude of apomorphine-induced excitation of pallidal neurons is influenced by the time schedule of drug administration.
D000818:Animals; D001058:Apomorphine / Q000008:administration & dosage / Q000494:pharmacology*; D004334:Drug Administration Schedule; D005917:Globus Pallidus / Q000187:drug effects*; D008297:Male; D009474:Neurons / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects; D013997:Time Factors
D011954:Receptors, Dopamine; D001058:Apomorphine