PT - JOURNAL ARTICLE AU - Min Jiang AU - Gong Chen TI - Ca<sup>2+</sup> Regulation of Dynamin-Independent Endocytosis in Cortical Astrocytes AID - 10.1523/JNEUROSCI.6139-08.2009 DP - 2009 Jun 24 TA - The Journal of Neuroscience PG - 8063--8074 VI - 29 IP - 25 4099 - http://www.jneurosci.org/content/29/25/8063.short 4100 - http://www.jneurosci.org/content/29/25/8063.full SO - J. Neurosci.2009 Jun 24; 29 AB - Astrocytes release ATP and glutamate through vesicular exocytosis to mediate neuron–glial interactions. In contrast to exocytosis, the endocytic pathways in astroglial cells are poorly understood. Here, we identify a constitutive endocytic pathway in cultured astrocytes that is dependent on neither clathrin nor dynamin. This dynamin-independent endocytic pathway is regulated by Rab5, an early endosome protein. The endocytosed vesicles show fast transition from early endosomes to late endosomes and lysosomes within a few minutes. Interestingly, this clathrin- and dynamin-independent endocytosis in astrocytes is potently regulated by intracellular Ca2+. ATP and glutamate greatly enhance the dynamin-independent endocytosis through elevating the intracellular Ca2+. In addition, amyloid-β peptide (Aβ) also enhances the dynamin-independent endocytosis by inducing Ca2+ transients in astrocytes. These results demonstrate a novel endocytic pathway in glial cells that is dynamin independent but tightly regulated by intracellular Ca2+. The regulation by ATP, glutamate, and Aβ suggests an important role of the dynamin-independent endocytosis in both physiological and pathological conditions.