Astrocytes contain a vesicular compartment that is competent for regulated exocytosis of glutamate.

Details

Serval ID
serval:BIB_A82CA28AE474
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Astrocytes contain a vesicular compartment that is competent for regulated exocytosis of glutamate.
Journal
Nature Neuroscience
Author(s)
Bezzi P., Gundersen V., Galbete J.L., Seifert G., Steinhäuser C., Pilati E., Volterra A.
ISSN
1097-6256 (Print)
ISSN-L
1097-6256
Publication state
Published
Issued date
2004
Volume
7
Number
6
Pages
613-620
Language
english
Abstract
Astrocytes establish rapid cell-to-cell communication through the release of chemical transmitters. The underlying mechanisms and functional significance of this release are, however, not well understood. Here we identify an astrocytic vesicular compartment that is competent for glutamate exocytosis. Using postembedding immunogold labeling of the rat hippocampus, we show that vesicular glutamate transporters (VGLUT1/2) and the vesicular SNARE protein, cellubrevin, are both expressed in small vesicular organelles that resemble synaptic vesicles of glutamatergic terminals. Astrocytic vesicles, which are not as densely packed as their neuronal counterparts, can be observed in small groups at sites adjacent to neuronal structures bearing glutamate receptors. Fluorescently tagged VGLUT-containing vesicles were studied dynamically in living astrocytes by total internal reflection fluorescence (TIRF) microscopy. After activation of metabotropic glutamate receptors, astrocytic vesicles underwent rapid (milliseconds) Ca(2+)- and SNARE-dependent exocytic fusion that was accompanied by glutamate release. These data document the existence of a Ca(2+)-dependent quantal glutamate release activity in glia that was previously considered to be specific to synapses.
Keywords
Animals, Astrocytes/metabolism, Astrocytes/secretion, Carrier Proteins/biosynthesis, Carrier Proteins/genetics, Cells, Cultured, Exocytosis/physiology, Glutamic Acid/metabolism, Glutamic Acid/secretion, Hippocampus/metabolism, Hippocampus/secretion, Membrane Proteins/biosynthesis, Membrane Proteins/genetics, Membrane Transport Proteins, Rats, Synaptic Vesicles/metabolism, Synaptic Vesicles/secretion, Transport Vesicles/metabolism, Transport Vesicles/secretion, Vesicle-Associated Membrane Protein 3, Vesicular Glutamate Transport Protein 1, Vesicular Glutamate Transport Protein 2, Vesicular Transport Proteins
Pubmed
Web of science
Create date
24/01/2008 14:37
Last modification date
20/08/2019 15:12
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