PT  - JOURNAL ARTICLE
AU  - D K Pitts
AU  - M D Kelland
AU  - A S Freeman
AU  - L A Chiodo
TI  - Repeated amphetamine administration: role of forebrain in reduced responsiveness of nigrostriatal dopamine neurons to dopamine agonists.
DP  - 1993 Feb 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 616--621
VI  - 264
IP  - 2
4099  - http://jpet.aspetjournals.org/content/264/2/616.short
4100  - http://jpet.aspetjournals.org/content/264/2/616.full
SO  - J Pharmacol Exp Ther1993 Feb 01; 264
AB  - The effects of repeated amphetamine treatment on single antidromically identified nigrostriatal dopamine-containing (NSDA) neurons were evaluated in rats. The inhibitory potency and efficacy of dopamine (DA) agonists on NSDA neuron spontaneous discharge rate were examined after amphetamine treatment. Repeated amphetamine treatment (14 days, 1 or 6 mg/kg/day i.p.) dose-dependently decreased the sensitivity of NSDA neurons to the inhibitory effects of the i.v. administered quinpirole. The amphetamine-induced alteration in sensitivity to apomorphine and quinpirole was abolished by acute hemitransection of the forebrain/midbrain connections. No change in the responsiveness or sensitivity of NSDA neurons to the inhibitory effects of iontophoretically applied DA was detected after amphetamine treatment for 14 days (4 or 6 mg/kg/day) or 28 days (6 mg/kg/day). These results suggest that these amphetamine regimens alter the sensitivity/responsiveness of forebrain DA receptors but not NSDA cell somatodendritic DA autoreceptors in a dose-dependent manner.