GLT-1 down-regulation induced by clozapine in rat frontal cortex is associated with synaptophysin up-regulation.
J Neurochem
; 99(1): 134-41, 2006 Oct.
Article
em En
| MEDLINE
| ID: mdl-16987241
ABSTRACT
In rat frontal cortex, extracellular levels of glutamate are raised by the anti-psychotic drug clozapine. We have recently shown that a significant reduction in the levels of the glutamate transporter GLT-1 may be one of the mechanisms responsible for this elevation. Here we studied whether GLT-1 down-regulation induced by chronic clozapine treatment is associated with changes in the expression of synaptophysin, synaptosome-associated protein of 25 kDa (SNAP-25) and vesicular glutamate transporter 1 (VGLUT1), three major presynaptic proteins involved in neurotransmitter release. Quantitative high-resolution confocal microscopy studies in vivo showed that GLT-1 down-regulation is closely associated with a significant increase in synaptophysin, but not SNAP-25 and VGLUT1, expression. This was confirmed in vitro studies, and in western blotting studies of synaptophysin, SNAP-25 and VGLUT1. In addition, our results show that, following clozapine treatment, synaptophysin expression increases in the very cortical regions in which GLT-1 expression is down-regulated. These findings suggest that part of the effects of clozapine may be exerted via an action on the presynaptic machinery involved in neurotransmitter release.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Regulação da Expressão Gênica
/
Sinaptofisina
/
Clozapina
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Transportador 2 de Aminoácido Excitatório
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Lobo Frontal
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2006
Tipo de documento:
Article