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Vladimir Parpura"Spatio-temporal characteristics of exocytosis in astrocytes"

Abstract :


The mechanism underlying calcium-dependent release of various transmitters from astrocytes is exocytosis.
Astrocytes express the protein components of the SNARE complex, including synaptobrevin 2, syntaxin and SNAP-23, but not SNAP-25. Using astrocytes expressing synapto-pHluorin, exoctytotic sites can be fluorescently imaged. Solitary astrocytes predominantly exhibit exocytotic fusion sites at the plasma membrane in the perinuclear region of the astrocytes, while astrocytes in contact with other cells show their fusion sites evenly distributed between the central and peripheral (location of cell-cell contact) regions; this contact-directed distribution of fusion sites is regulated by the gap junction protein, connexin 43. Fusions of synapto-pHluorin labeled vesicles with the plasma membrane can be observed using total internal reflection fluorescence microscopy; the time course of fusion events (burst vs. sustained), their type (“kiss-and-run” vs. full fusion) and spatial relationship between different fusion sites is discussed. 

Selected publications

Ni Y, Malarkey EB, Parpura V.
Vesicular release of glutamate mediates bidirectional signaling between astrocytes and neurons.
J Neurochem. 2007 Aug 28; [Epub ahead of print]
Malarkey EB, Parpura V.
Mechanisms of glutamate release from astrocytes.
Neurochem Int. 2007 Jun 26; [Epub ahead of print]
Malarkey EB, Parpura V.
Applications of carbon nanotubes in neurobiology.
Neurodegener Dis. 2007;4(4):292-9.
PMID: 17627132 [PubMed - in process]

Jean Pierre Mothet