ISSN:
1432-1912
Keywords:
GABA
;
Muscimol
;
Substantia nigra zona reticulata
;
Long-term treatment
;
Methamphetamine
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The effects of chronic administration of methamphetamine on the responsiveness of neurons of the substantia nigra zona reticulata (SNR) to gammaaminobutyric acid (GABA) or to a GABA receptor agonist were examined. Neuronal activity was recorded from the SNR of rats that had been pretreated twice daily, for 6 consecutive days, with saline or with 5 mg/kg methamphetamine. Intravenous administration of the GABA receptor agonist, muscimol, caused a dose-dependent decrease in the unit activity of the SNR neurons and the SNR neurons became less sensitive to the depressant effects of the drug after chronic treatment with methamphetamine. Iontophoretic application, with increasing currents, of GABA produced a progressive inhibition of unit activity in control animals, an effect that was significantly reduced in rats pretreated with methamphetamine. These results support the hypothesis that long-term administration of methamphetamine increases the activity of the striatonigral GABA system and thereby reduces the sensitivity of postsynaptic GABA receptors in the SNR.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00569386
