Acute Ethanol Exposure Induces [Ca2+]i Transients, Cell Swelling and Transformation of Actin Cytoskeleton in Astroglial Primary Cultures

Acute exposure to 100 mM isotonic ethanol (EtOH) increased intracellular Ca2+ concentration ([Ca2+]i), induced cell swelling, and transformed actin cytoskeleton in astroglial primary cultures from rat cerebral cortex. Fluorometric recordings of fluo-3AM- or fura-2AM-incubated astroglial cells revealed that EtOH induced [Ca2+]i transients in a small population of the cells. Cell swelling was estimated using a new method based on three-dimensional fluorescence imaging in conjunction with image analysis and graphic visualization techniques. The method provides detailed results concerning the reformation of structural shape and specific volume alterations, as well as total proportions between the different states. Astroglial cell swelling was registered and quantified in 7 of 39 cells chosen from 12 different coverslips. EtOH also induced reversible conformational changes in filamentous actin, appearing as increases in ring formations and a more dispersed appearance of the filaments. Filamentous actin was stained with Alexa phalloidin after incubation with EtOH for varied periods. The results presented here suggest that EtOH affects astrocytes in a way that could be of physiological relevance.