Avtor/Urednik | Parpura, Vladimir; Grubišić, Vladimir; Verkhratsky, Alexei | |
Naslov | Ca[sup]2+ sources for the exocytotic release of glutamate from astrocytes | |
Tip | članek | |
Vol. in št. | Letnik 1813, št. 5 | |
Leto izdaje | 2011 | |
Obseg | str. 984-991 | |
ISSN | 0167-4838 - Biochimica et biophysica acta | |
Jezik | eng | |
Abstrakt | Astrocytes can exocytotically release the gliotransmitter glutamate from vesicular compartments. Increased cytosolic Ca(2+) concentration is necessary and sufficient for this process. The predominant source of Ca(2+) for exocytosis in astrocytes resides within the endoplasmic reticulum (ER). Inositol 1,4,5-trisphosphate and ryanodine receptors of the ER provide a conduit for the release of Ca(2+) to the cytosol. The ER store is (re)filled by the store-specific Ca(2+)-ATPase. Ultimately, the depleted ER is replenished by Ca(2+) which enters from the extracellular space to the cytosol via store-operated Ca(2+) entry; the TRPC1 protein has been implicated in this part of the astrocytic exocytotic process. Voltage-gated Ca(2+) channels and plasma membrane Na(+)/Ca(2+) exchangers are additional means for cytosolic Ca(2+) entry. Cytosolic Ca(2+) levels can be modulated by mitochondria, which can take up cytosolic Ca(2+) via the Ca(2+) uniporter and release Ca(2+) into cytosol via the mitochondrial Na(+)/Ca(2+) exchanger, as well as by the formation of the mitochondrial permeability transition pore. The interplay between various Ca(2+) sources generates cytosolic Ca(2+) dynamics that can drive Ca(2+)-dependent exocytotic release of glutamate from astrocytes. An understanding of this process in vivo will reveal some of the astrocytic functions in health and disease of the brain. | |
Proste vsebinske oznake | astrocyte endoplasmic reticulum mitochondria astrocit endoplazemski retikulum mitohondrij |