title: "Kiss-and-run" glutamate secretion in cultured and freshly isolated rat hippocampal astrocytes.
abstract: Under physiological conditions, astrocytes not only passively support and nourish adjacent neurons, but also actively modulate neuronal transmission by releasing "glial transmitters," such as glutamate, ATP, and D-serine. Unlike the case for neurons, the mechanisms by which glia release transmitters are essentially unknown. Here, by using electrochemical amperometry and frequency-modulated single-vesicle imaging, we discovered that hippocampal astrocytes exhibit two modes of exocytosis of glutamate in response to various stimuli. After physiological stimulation, a glial vesicle releases a quantal content that is only 10% of that induced by nonphysiological, mechanical stimulation. The small release event arises from a brief (approximately 2 ms) opening of the fusion pore. We conclude that, after physiological stimulation, astrocytes release glutamate via a vesicular "kiss-and-run" mechanism.
authors.affiliation: Institute of Molecular Medicine, Peking University, Beijing 100871, China.
authors.forename: Xiaoke
authors.initials: X
authors.lastname: Chen
authors.forename: Liecheng
authors.initials: L
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhou
authors.forename: Liang-Hong
authors.initials: LH
authors.lastname: Zheng
authors.forename: Zhuan
authors.initials: Z
authors.lastname: Zhou
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D019439:Chromaffin Cells / Q000187:drug effects / Q000502:physiology; D003952:Diagnostic Imaging / Q000379:methods; D004298:Dopamine / Q000494:pharmacology; D004563:Electrochemistry / Q000379:methods; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism* / Q000494:pharmacology*; D006624:Hippocampus / Q000166:cytology*; D007150:Immunohistochemistry / Q000379:methods; D008854:Microscopy, Electron / Q000379:methods; D018408:Patch-Clamp Techniques / Q000379:methods; D010812:Physical Stimulation / Q000379:methods; D011726:Pyridinium Compounds / Q000378:metabolism / Q000494:pharmacology; D000644:Quaternary Ammonium Compounds / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013744:Tetanus Toxin / Q000494:pharmacology
chemical_list: C073804:FM1 43; D005904:Glial Fibrillary Acidic Protein; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; D013744:Tetanus Toxin; D018698:Glutamic Acid; D002118:Calcium; D004298:Dopamine