A novel optical intracellular imaging approach for potassium dynamics in astrocytes.

Détails

Ressource 1Télécharger: BIB_EEC9B1BB37A5.P001.pdf (759.03 [Ko])
Etat: Public
Version: de l'auteur
ID Serval
serval:BIB_EEC9B1BB37A5
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
A novel optical intracellular imaging approach for potassium dynamics in astrocytes.
Périodique
Plos One
Auteur(s)
Rimmele T.S., Chatton J.Y.
ISSN
1932-6203 (Electronic)
ISSN-L
1932-6203
Statut éditorial
Publié
Date de publication
2014
Peer-reviewed
Oui
Volume
9
Numéro
10
Pages
e109243
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't Publication Status: epublish
Résumé
Astrocytes fulfill a central role in regulating K+ and glutamate, both released by neurons into the extracellular space during activity. Glial glutamate uptake is a secondary active process that involves the influx of three Na+ ions and one proton and the efflux of one K+ ion. Thus, intracellular K+ concentration ([K+]i) is potentially influenced both by extracellular K+ concentration ([K+]o) fluctuations and glutamate transport in astrocytes. We evaluated the impact of these K+ ion movements on [K+]i in primary mouse astrocytes by microspectrofluorimetry. We established a new noninvasive and reliable approach to monitor and quantify [K+]i using the recently developed K+ sensitive fluorescent indicator Asante Potassium Green-1 (APG-1). An in situ calibration procedure enabled us to estimate the resting [K+]i at 133±1 mM. We first investigated the dependency of [K+]i levels on [K+]o. We found that [K+]i followed [K+]o changes nearly proportionally in the range 3-10 mM, which is consistent with previously reported microelectrode measurements of intracellular K+ concentration changes in astrocytes. We then found that glutamate superfusion caused a reversible drop of [K+]i that depended on the glutamate concentration with an apparent EC50 of 11.1±1.4 µM, corresponding to the affinity of astrocyte glutamate transporters. The amplitude of the [K+]i drop was found to be 2.3±0.1 mM for 200 µM glutamate applications. Overall, this study shows that the fluorescent K+ indicator APG-1 is a powerful new tool for addressing important questions regarding fine [K+]i regulation with excellent spatial resolution.
Pubmed
Web of science
Open Access
Oui
Création de la notice
13/01/2015 8:13
Dernière modification de la notice
20/08/2019 16:16
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