Differential effects of glutamate transporter inhibitors on the global electrophysiological response of astrocytes to neuronal stimulation

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Etat: Public
Version: Author's accepted manuscript
ID Serval
serval:BIB_76E5946E1998
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Differential effects of glutamate transporter inhibitors on the global electrophysiological response of astrocytes to neuronal stimulation
Périodique
Brain Research
Auteur⸱e⸱s
Bernardinelli Y., Chatton J. Y.
ISSN
1872-6240
Statut éditorial
Publié
Date de publication
11/2008
Peer-reviewed
Oui
Volume
1240
Pages
47-53
Langue
anglais
Résumé
Astrocytes are responsible for regulating extracellular levels of glutamate and potassium during neuronal activity. Glutamate clearance is handled by glutamate transporter subtypes glutamate transporter 1 and glutamate-aspartate transporter in astrocytes. DL-threo-beta-benzyloxyaspartate (TBOA) and dihydrokainate (DHK) are extensively used as inhibitors of glial glutamate transport activity. Using whole-cell recordings, we characterized the effects of both transporter inhibitors on afferent-evoked astrocyte currents in acute cortical slices of 3-week-old rats. When neuronal afferents were stimulated, passive astrocytes responded by a rapid inward current followed by a persistent tail current. The first current corresponded to a glutamate transporter current. This current was inhibited by both inhibitors and by tetrodotoxin. The tail current is an inward potassium current as it was blocked by barium. Besides inhibiting transporter currents, TBOA strongly enhanced the tail current. This effect was barium-sensitive and might be due to a rise in extracellular potassium level and increased glial potassium uptake. Unlike TBOA, DHK did not enhance the tail current but rather inhibited it. This result suggests that, in addition to inhibiting glutamate transport, DHK prevents astrocyte potassium uptake, possibly by blockade of inward-rectifier channels. This study revealed that, in brain slices, glutamate transporter inhibitors exert complex effects that cannot be attributed solely to glutamate transport inhibition.
Pubmed
Web of science
Open Access
Oui
Création de la notice
30/01/2009 10:13
Dernière modification de la notice
20/08/2019 14:33
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