GABAA increases calcium in subventricular zone astrocyte-like cells through L- and T-type voltage-gated calcium channels

Frontiers in Cellular Neuroscience

Jakob VNielsen¹  Niels AJensen¹  Stephanie ZYoung²  Angelique Bordey²  Jean-Claude Platel² 

[1] Molecular Neurobiology Laboratory,Medical Biotechnology Center,University of Southern Denmark;Yale University School of Medicine;

关键词: Neurogenesis;    Stem Cells;    GABA;    astrocyte;    proliferation;    progenitor cells;   

DOI  :  10.3389/fncel.2010.00008

来源: DOAJ

【 摘 要 】

In the adult neurogenic subventricular zone (SVZ), the behavior of astrocyte-like cells and some of their functions depend on changes in intracellular Ca2+ levels and tonic GABA_A receptor activation. However, it is unknown whether, and if so how, GABA_A receptor activity regulates intracellular Ca2+ dynamics in SVZ astrocytes. To monitor Ca2+ activity selectively in astrocyte-like cells, we used two lines of transgenic mice expressing either GFP fused to a Gq-coupled receptor or DsRed under the human glial fibrillary acidic protein (hGFAP) promoter. GABA_A receptor activation induced Ca2+ increases in 40-50% of SVZ astrocytes. GABA_A-induced Ca2+ increases were prevented with nifedipine and mibefradil, blockers of L- and T-type voltage-gated calcium channels (VGCC). The L-type Ca2+ channel activator BayK 8644 increased the percentage of GABAA-responding astrocyte-like cells to 75%, suggesting that the majority of SVZ astrocytes express functional VGCCs. SVZ astrocytes also displayed spontaneous Ca2+ activity, the frequency of which was regulated by tonic GABA_A receptor activation. These data support a role for ambient GABA in tonically regulating intracellular Ca2+ dynamics through GABA_A receptors and VGCC in a subpopulation of astrocyte-like cells in the postnatal SVZ.

【 授权许可】

Unknown