GABA release mechanism in the golden hamster retina.
Int J Neurosci
; 98(1-2): 13-25, 1999.
Article
em En
| MEDLINE
| ID: mdl-10395361
ABSTRACT
High K+ medium and glutamate elicited a significant [3H]-GABA release in the golden hamster retina. High K+ -induced GABA release was largely calcium-dependent, while the effect of glutamate was Ca2+ -independent. After replacing Na+ by Li+, glutamate-evoked [3H]-GABA release was abolished, while high K+ -evoked release remained unchanged. The effect of glutamate was completely blocked by DNQX but not by APV. Furthermore, kainate induced [3H]-GABA release, whereas NMDA was ineffective. Assessment of endogenous GABA efflux further confirmed results obtained for [3H]-GABA. GABA-like immunoreactivity was observed in amacrine cells, in neurons localized in ganglion cell layer, as well as in fibers and terminals at the inner plexiform layer. In addition a few horizontal cells showed GABA-like immunolabeling. The present results suggest the existence of at least two pools of GABA in the hamster retina, compatible with both vesicular and carrier-mediated mechanisms of transmitter release, being the amacrine cells the main gabaergic source in this tissue.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Retina
/
Ácido gama-Aminobutírico
Limite:
Animals
Idioma:
En
Revista:
Int J Neurosci
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Argentina