LONG-TERM ETHANOL-EXPOSURE MARKEDLY CHANGES THE CELLULAR COMPOSITION OF CEREBRAL GLIAL CULTURES

The vulnerablity of morphologically distinct glial subpopulations to ethanol toxicity was surveyed in tissue culture. Secondary cultures of rat glia were examined at intervals during 56 days of ethanol treatment for changes in growth and cellular characteristics. Beginning at 6 days in vitro (DIV), the experimental cultures were treated with either 0.2% or 0.5% (w/v) ethanol in the medium; control cultures received ethanol-free medium. Relative to control cultures, the ethanol-treated cultures exhibited a consistent and dose-dependent suppression in cell number. The development of these cultures was documented with sequential phase-contrast photomicrography. Prior to treatment day 5 (11 DIV), the preponderance of cells were epithelioid in configuration; the astrocytic character of these cells was verified by the immunocytochemical localization of glial fibrillary acidic protein. In control cultures, a subpopulation of process-bearing cells was acquired gradually during the first 3 weeks in culture. The majority of these process-bearing cells were considered to be oligodendrocytes due to their position above the astrocytic carpet and by the immunocytochemical localization galactocerebroside. Exposure to 0.5% ethanol markedly suppressed the acquisition of process-bearing cells. This ethanol-related suppression of process-bearing cells was apparent in the photomicrographic records of culture development and was confirmed by differential cell counts after 50 days of treatment. These results suggest a possible differential sensitivity of oligodendrocytes or their precursors to ethanol toxicity at elevated (0.5% w/v) concentrations.