Receptor-mediated glutamate release from volume sensitive channels in astrocytes
| Autor: | Takahiro Takano, Jian Kang, Jyoti K. Jaiswal, Sanford M. Simon, Jane H.-C. Lin, Yufei Yu, Yuxing Li, Jay Yang, Gerald Dienel, H. Ronald Zielke, Maiken Nedergaard |
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| Rok vydání: | 2005 |
| Předmět: |
Glutamic Acid
Biology Exocytosis Ion Channels Rats Sprague-Dawley Adenosine Triphosphate Glutamate aspartate transporter Animals Ion channel Cell Size Multidisciplinary Receptors Purinergic P2 Glutamate receptor Glutamic acid Biological Sciences Rats Biochemistry Osmolyte Metabotropic glutamate receptor Astrocytes Connexin 43 Biophysics biology.protein NMDA receptor Calcium |
| Zdroj: | Proceedings of the National Academy of Sciences. 102:16466-16471 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.0506382102 |
| Popis: | Several lines of work have shown that astrocytes release glutamate in response to receptor activation, which results in a modulation of local synaptic activity. Astrocytic glutamate release is Ca 2+ -dependent and occurs in conjunction with exocytosis of glutamate containing vesicles. However, astrocytes contain a millimolar concentration of cytosolic glutamate and express channels permeable to small anions, such as glutamate. Here, we tested the idea that astrocytes respond to receptor stimulation by dynamic changes in cell volume, resulting in volume-sensitive channel activation, and efflux of cytosolic glutamate. Confocal imaging and whole-cell recordings demonstrated that astrocytes exhibited a transient Ca 2+ -dependent cell volume increase, which activated glutamate permeable channels. HPLC analysis revealed that glutamate was released in conjunction with other amino acid osmolytes. Our observations indicate that volume-sensitive channel may constitute a previously uncharacterized target for modulation of astrocyte-neuronal interactions. |
| Databáze: | OpenAIRE |
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