Effect of continuous systemic infusion of D-amphetamine on the sensitivity of nigral dopamine cells to apomorphine inhibition of firing rates.
Using a single-unit recording technique, sensitivity of nigral dopamine neurons to the inhibitory effect of apomorphine was examined on various days after a 7-day pretreatment with osmotic minipumps containing D-amphetamine. Continuous systemic infusion of D-amphetamine produced a short-lasting subsensitivity of nigral neurons to apomorphine (0-2 days after D-amphetamine), followed by a supersensitivity on days 7, 8 and 9, post-amphetamine. The supersensitivity seems to persist at least for one week, suggesting one possible mechanism mediating long-term behavioral and biochemical changes following chronic high-dose amphetamine administration.
D000818:Animals; D001058:Apomorphine / Q000008:administration & dosage*; D003913:Dextroamphetamine / Q000008:administration & dosage*; D004298:Dopamine / Q000378:metabolism / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013378:Substantia Nigra / Q000187:drug effects* / Q000378:metabolism
D001058:Apomorphine; D003913:Dextroamphetamine; D004298:Dopamine