Apparent desensitization of NMDA responses in Xenopus oocytes involves calcium-dependent chloride current.
Neuron
; 4(1): 53-60, 1990 Jan.
Article
em En
| MEDLINE
| ID: mdl-1690016
ABSTRACT
N-Methyl-D-aspartate (NMDA) receptors were expressed and studied in Xenopus oocytes injected with rat brain RNA. NMDA application elicits a rapid inward current that decays in several seconds to a relatively stable level. This decay is reportedly due to desensitization. However, we found the early transient component could be evoked more than once during a single application of NMDA, suggesting that the receptor did not actually desensitize. Removal of external Ca2+, replacement of Ca2+ with Ba2+, or intracellular injection of EGTA abolished the transient component. Furthermore, a variety of Cl- channel blockers nearly eliminated the transient component and inhibited the plateau current as well. We propose that a significant portion of the NMDA current recorded in oocytes is carried by a transient inward Cl- current triggered by Ca2+ influx through the NMDA receptor/channel.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oócitos
/
Cloretos
/
Cálcio
/
Receptores de Neurotransmissores
Limite:
Animals
Idioma:
En
Ano de publicação:
1990
Tipo de documento:
Article