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Modulation of dendritic release of dopamine by N-methyl-D-aspartate receptors in rat substantia nigra.

Modulation of dendritic release of dopamine by N-methyl-D-aspartate receptors in rat substantia nigra.

Authors :
Araneda R
Bustos G
Source :
Journal of neurochemistry [J Neurochem] 1989 Mar; Vol. 52 (3), pp. 962-70.
Publication Year :
1989

Abstract

A superfusion system was used to study the effects of excitatory amino acids (EAA) on release of [3H]dopamine ([3H]DA) previously taken up by rat substantia nigra (SN) slices. The EAA tested (20-250 microM), with the exception of quisqualate and kainate, markedly evoked [3H]DA release from nigral slices when Mg2+ ions were omitted from the superfusion medium. The EAA receptor agonists exhibited the following relative potency in stimulating [3H]DA release: L-glutamate (L-Glu) greater than N-methyl-D-aspartate (NMDA) greater than NM(D,L)A greater than D-Glu much greater than quisqualate = kainate. D-2-Amino-5-phosphonovalerate (100-200 microM), an antagonist for NMDA receptors, substantially reduced [3H]DA release evoked by L-Glu or NMDA. In contrast, L-Glu diethyl ester (100-200 microM) produced a lesser blocking effect on [3H]DA release evoked by the EAA. Further experiments showed that the NMDA-mediated release of [3H]DA was totally suppressed by the omission of Ca2+ or by the addition of tetrodotoxin (0.1 microM) to the superfusion medium. In addition, strychnine, an antagonist for glycine (Gly) receptors, significantly decreased NMDA (100 microM)-evoked as well as glycine (100 microM)-evoked release of [3H]DA from nigral slices. The results shown support the idea that activation of NMDA subtype receptors in SN may trigger a Ca2+-dependent release of DA from dendrites of nigro-striatal DA-containing neurons. Furthermore, a transsynaptic mechanism that may partially involve Gly-containing interneurons is proposed to account for some of the events mediating NMDA receptor activation and DA release in SN.

Details

Language :
English
ISSN :
0022-3042
Volume :
52
Issue :
3
Database :
MEDLINE
Journal :
Journal of neurochemistry
Publication Type :
Academic Journal
Accession number :
2563759
Full Text :
https://doi.org/10.1111/j.1471-4159.1989.tb02548.x