Astrocyte swelling leads to membrane unfolding, not membrane insertion.

摘要: The mechanisms mediating the release of chemical transmitters from astrocytes are subject intense research. Recent experiments have shown that hypotonic conditions stimulate glutamate and ATP astrocytes, but a mechanistic understanding this process is not available. To determine whether hypotonicity activates regulated exocytosis, we monitored membrane capacitance by whole-cell patch-clamp technique whilst medium was applied to cultured astrocytes. If exocytosis triggered under conditions, as it following increases in cytosolic calcium, net increase surface area, measuring capacitance, expected. Simultaneous measurements cell size conductance area demonstrated (210 mOsm for 200 s) resulted an swelling average 40%, cross-sectional without any corresponding change area. As sensitivity detect small 0.5%, conclude occurs via exocytosis-independent mechanism, probably involving unfolding plasma membrane.