Functional and biochemical characteristics of a putative quisqualate-type receptor in rat striatum: effect of brain lesions.
Excitatory amino acids such as L-glutamate (Glu) and quisqualate (QUIS) markedly potentiated K+-evoked release of exogenous [3H]dopamine (DA) from rat striatal slices. Intrastriatal kainic acid injections resulted in a total disappearance of the stimulatory effects of Glu on evoked-release of [3H]DA as well as in a parallel reduction in the maximal number (Bmax) of a D-aspartate-insensitive L-[3H]Glu binding site in striatal particulate fractions. Following cortical ablation, the potentiating effect of Glu on [3H]DA release in decorticated striatal slices lasted longer, compared to normal slices, and occurred during the 2nd min following K+-depolarization. However, the extent (%) of Glu stimulation on [3H]DA release remained the same in decorticated and normal striatal slices. Cortical ablation produced also a significant decrease in the Bmax and in the KD' of the D-aspartate-insensitive binding site towards L-[3H]Glu. These results support the proposal that the D-aspartate-insensitive Glu binding site is somehow related to an amino acid receptor-mediated modulation of dopaminergic transmission in the rat corpus striatum.
Rudolph
M I
MI
Department of Cell Biology, Pontificia Universidad Católica de Chile, Santiago.
Bustos
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D000818:Animals; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D001921:Brain / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology; D003292:Convulsants / Q000494:pharmacology; D003342:Corpus Striatum / Q000187:drug effects / Q000502:physiology*; D004298:Dopamine / Q000378:metabolism; D005971:Glutamates / Q000494:pharmacology; D066298:In Vitro Techniques; D007608:Kainic Acid / Q000494:pharmacology; D008297:Male; D016202:N-Methylaspartate; D010069:Oxadiazoles / Q000378:metabolism / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology; D016318:Quisqualic Acid; D051381:Rats; D011919:Rats, Inbred Strains; D018091:Receptors, AMPA; D011955:Receptors, Drug / Q000187:drug effects / Q000502:physiology*
D003292:Convulsants; D005971:Glutamates; D010069:Oxadiazoles; D018091:Receptors, AMPA; D011955:Receptors, Drug; D001224:Aspartic Acid; D016202:N-Methylaspartate; D016318:Quisqualic Acid; D011188:Potassium; D007608:Kainic Acid; D004298:Dopamine