Nigral dopaminergic neurons: differential sensitivity to apomorphine following long-term treatment with low and high doses of amphetamine.
Twice daily injections of 1.0 or 5.0 mg/kg D-amphetamine for 6 consecutive days differentially affected the response of dopaminergic neurons in the substantia nigra pars compacta to challenge injections of apomorphine on the following day. Thus, whereas treatment with the high amphetamine dose produced a dramatic shift to the right of the apomorphine dose-response curve, rats treated with 1.0 mg/kg D-amphetamine responded to apomorphine in the same way as saline-treated controls. These results support the view that long-term treatment with relatively high amphetamine doses is required to produce autoreceptor subsensitivity in the substantia nigra.
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D003913:Dextroamphetamine / Q000494:pharmacology*; D004298:Dopamine / Q000502:physiology*; D004347:Drug Interactions; D008297:Male; D051381:Rats; D013378:Substantia Nigra / Q000187:drug effects*
D001058:Apomorphine; D003913:Dextroamphetamine; D004298:Dopamine