Mild brain ischemia induces unique physiological properties in striatal astrocytes

Item Type:	Article
Title:	Mild brain ischemia induces unique physiological properties in striatal astrocytes
Creators Name:	Wang, L.P. and Cheung, G. and Kronenberg, G. and Gertz, K. and Ji, S. and Kempermann, G. and Endres, M. and Kettenmann, H.
Abstract:	We studied the properties of GFAP-expressing cells in adult mouse striatum using acute brain slices from transgenic animals expressing EGFP under GFAP promoter. Under physiological conditions, two distinct populations of GFAP-EGFP cells could be identified: (1) brightly fluorescent cells had bushy processes, passive membrane properties, glutamate transporter activity, and high gap junction coupling rate typical for classical astrocytes; (2) weakly fluorescent cells were characterized by thin, clearly distinguishable processes, voltage-gated currents, complex responses to kainate, and low coupling rate reminiscent of an astrocyte subtype recently described in the hippocampus. Mild focal cerebral ischemia confers delayed neuronal cell death and astrogliosis in the striatum. Following middle cerebral artery occlusion and reperfusion, brightly fluorescent cells were the dominant GFAP-EGFP population observed within the ischemic lesion. Interestingly, the majority of these cells expressed voltage-gated channels, showed complex responses to kainate, and a high coupling rate exceeding that of brightly fluorescent control cells. A minority of cells had passive membrane properties and was coupled less compared with passive control cells. We conclude that, in the adult striatum, astrocytes undergo distinct pathophysiological changes after ischemic insults. The dominant population in the ischemic lesion constitutes a novel physiological phenotype unlike any normal astrocyte and generates a large syncytium which might be a neuroprotective response of reactive astrocytes.
Keywords:	Gap Junction, Glutamate Receptor, Membrane Current, Striatum, Animals, Mice
Source:	Glia
ISSN:	0894-1491
Publisher:	Wiley
Volume:	56
Number:	9
Page Range:	925-934
Date:	July 2008
Official Publication:	https://doi.org/10.1002/glia.20660
PubMed:	View item in PubMed

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