Tonically active GABA A receptors: modulating gain and maintaining the tone.
Trends Neurosci
; 27(5): 262-9, 2004 May.
Article
em En
| MEDLINE
| ID: mdl-15111008
ABSTRACT
GABAA receptors not only respond to the local release of GABA from presynaptic terminals, but can also mediate a persistent 'tonic current'. This reflects the activation of high-affinity GABAA receptors by ambient GABA concentrations. Tonic GABAA-receptor-mediated signalling occurs in different brain regions, shows cell-type-specific differences in magnitude and pharmacology, and changes during brain development. Some clues to the adaptive significance of this phenomenon are beginning to emerge in cerebellar granule cells, it alters the gain of transmission of rate-coded sensory information; in the hippocampus, it acts in a cell-type-specific manner to regulate the excitability of the network. Because tonic conductances can be modulated by changes in GABA release and uptake, and by modulators of high-affinity GABAA receptors including neurosteroids, this phenomenon provides a potentially important new window onto neuronal information processing and pathological states such as epilepsy.
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Bases de dados:
MEDLINE
Assunto principal:
Encéfalo
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Potenciais de Ação
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Receptores de GABA-A
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Ácido gama-Aminobutírico
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Neurônios
Limite:
Animals
Idioma:
En
Revista:
Trends Neurosci
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Reino Unido