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 Ca 2+ concentration ([Ca2+](i)), induced cell swelling, and transformed actin cytoskeleton in astroglial primary cultures from rat cerebral cortex. Fluor ometric recordings of fluo-3AM- or fura-2AM-incubated astroglia[ cells reve aled that EtOH induced [Ca2+](i) transients in a small population of the ce lls. Cell swelling was estimated using a new method based on three-dimensio nal fluorescence imaging in conjunction with image analysis and graphic vis ualization 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 w as registered and quantified in 7 of 39 cells chosen from 12 different cove rslips. EtOH also induced reversible conformational changes in filamentous actin, appearing as increases in ring formations and a more dispersed appea rance 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 physiologica l relevance.