Repeated amphetamine: reduced dopamine neuronal responsiveness to apomorphine but not quinpirole.
Extracellular recordings from single nigrostriatal dopamine (DA) neurons in rats revealed significantly reduced neuronal sensitivity to the inhibitory effects of i.v. apomorphine following repeated amphetamine (4 mg/kg per day i.p., 14 days). This effect was reversed by acute SCH 23390. Quinpirole sensitivity was reduced in amphetamine-treated rats only following acute SKF 38393 pretreatment. These results suggest that, in amphetamine-treated animals, D-1 receptor activation is important for the expression of reduced nigrostriatal DA neuron sensitivity to apomorphine.
Pitts
D K
DK
Laboratory of Neurophysiology, Center for Cell Biology, Sinai Research Institute, Detroit, MI 48235.
Freeman
A S
AS
Kelland
M D
MD
Chiodo
L A
LA
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D001835:Body Weight / Q000187:drug effects; D004298:Dopamine / Q000378:metabolism*; D015259:Dopamine Agents / Q000494:pharmacology*; D004594:Electrophysiology; D004873:Ergolines / Q000494:pharmacology*; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D019257:Quinpirole; D051381:Rats; D011919:Rats, Inbred Strains
D015259:Dopamine Agents; D004873:Ergolines; D019257:Quinpirole; D000661:Amphetamine; D001058:Apomorphine; D004298:Dopamine