Fast subplasma membrane Ca2+ transients control exo-endocytosis of synaptic-like microvesicles in astrocytes

Détails

Ressource 1Télécharger: 18784293_Postprint.pdf (1220.12 [Ko])
Etat: Public
Version: Author's accepted manuscript
Document(s) secondaire(s)
Télécharger: 9122.full.pdf (509.11 [Ko])
Etat: Public
Version: Final published version
ID Serval
serval:BIB_2F626D4C12A2
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Fast subplasma membrane Ca2+ transients control exo-endocytosis of synaptic-like microvesicles in astrocytes
Périodique
Journal of Neuroscience
Auteur⸱e⸱s
Marchaland J., Cali C., Voglmaier S. M., Li H., Regazzi R., Edwards R. H., Bezzi P.
ISSN
1529-2401
Statut éditorial
Publié
Date de publication
2008
Peer-reviewed
Oui
Volume
28
Numéro
37
Pages
9122-9132
Langue
anglais
Résumé
Astrocytes are the most abundant glial cell type in the brain. Although not apposite for long-range rapid electrical communication, astrocytes share with neurons the capacity of chemical signaling via Ca(2+)-dependent transmitter exocytosis. Despite this recent finding, little is known about the specific properties of regulated secretion and vesicle recycling in astrocytes. Important differences may exist with the neuronal exocytosis, starting from the fact that stimulus-secretion coupling in astrocytes is voltage independent, mediated by G-protein-coupled receptors and the release of Ca(2+) from internal stores. Elucidating the spatiotemporal properties of astrocytic exo-endocytosis is, therefore, of primary importance for understanding the mode of communication of these cells and their role in brain signaling. We here take advantage of fluorescent tools recently developed for studying recycling of glutamatergic vesicles at synapses (Voglmaier et al., 2006; Balaji and Ryan, 2007); we combine epifluorescence and total internal reflection fluorescence imaging to investigate with unprecedented temporal and spatial resolution, the stimulus-secretion coupling underlying exo-endocytosis of glutamatergic synaptic-like microvesicles (SLMVs) in astrocytes. Our main findings indicate that (1) exo-endocytosis in astrocytes proceeds with a time course on the millisecond time scale (tau(exocytosis) = 0.24 +/- 0.017 s; tau(endocytosis) = 0.26 +/- 0.03 s) and (2) exocytosis is controlled by local Ca(2+) microdomains. We identified submicrometer cytosolic compartments delimited by endoplasmic reticulum tubuli reaching beneath the plasma membrane and containing SLMVs at which fast (time-to-peak, approximately 50 ms) Ca(2+) events occurred in precise spatial-temporal correlation with exocytic fusion events. Overall, the above characteristics of transmitter exocytosis from astrocytes support a role of this process in fast synaptic modulation.
Mots-clé
Analysis of Variance Animals Animals, Newborn Astrocytes/*cytology Calcium/*metabolism Calcium Signaling/drug effects/physiology Cell Membrane/drug effects/*physiology Cells, Cultured Dose-Response Relationship, Drug Endocytosis/drug effects/*physiology Glial Fibrillary Acidic Protein/metabolism Green Fluorescent Proteins/metabolism Kinetics Methoxyhydroxyphenylglycol/analogs & derivatives/pharmacology Rats Transfection/methods Vesicular Glutamate Transport Protein 1/genetics/metabolism
Pubmed
Web of science
Open Access
Oui
Création de la notice
30/01/2009 11:13
Dernière modification de la notice
20/08/2019 14:13
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