GABA(A) receptors in the pars compacta and GABA(B) receptors in the pars reticulata of rat substantia nigra modulate the striatal dopamine release.
The nigral GABAergic regulation of striatal dopamine release was investigated using voltammetry in freely moving rats. The local administration of muscimol (1 nM) in the substantia nigra pars compacta, but not in the substantia nigra pars reticulata, increased the striatal dopamine release. In contrast, the administration of baclofen (10 nM) in the substantia nigra pars reticulata, but not in the substantia nigra pars compacta, produced a decrease of the striatal dopamine release. Opposite effects were respectively observed after administration of GABA(A) and GABA(B) antagonists. These data lead us to suggest a differential presynaptic GABAergic control of the dopaminergic neurotransmission through GABA(A) receptors in the substantia nigra pars compacta, and GABA(B) receptors in the substantia nigra pars reticulata.
Balon
Norbert
N
Université de la Méditerranée et IMNSSA, E.A. 3280, Laboratoire de Physiopathologie et Action Thérapeutique des Gaz sous Pression, Faculté de Médecine Nord, IFR Jean Roche, Marseille, France.
Kriem
Badreddine
B
Weiss
Michel
M
Rostain
Jean-Claude
JC
D000818:Animals; D001418:Baclofen / Q000494:pharmacology; D001640:Bicuculline / Q000494:pharmacology; D003342:Corpus Striatum / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D004563:Electrochemistry; D008297:Male; D009118:Muscimol / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000502:physiology*; D018080:Receptors, GABA-B / Q000502:physiology*; D013378:Substantia Nigra / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*
D011963:Receptors, GABA-A; D018080:Receptors, GABA-B; D009118:Muscimol; D001418:Baclofen; D004298:Dopamine; D001640:Bicuculline