ETHANOL ENHANCES NEURITE OUTGROWTH IN PRIMARY CULTURES OF RAT CEREBELLAR MACRONEURONS

Effects of ethanol on neurite outgrowth and morphometry were investigated in primary cultures of rat cerebella. Cell cultures were prepared from cerebella on embryonic day 17 (El7) for treatment with a series of ethanol concentrations (50, 75, 100, 150 and 200 mM). Ethanol did not reduce neuronal survival or attachment to the substrate at any of the concentrations that were used. Treatment with 75 mM ethanol significantly enhanced neurite outgrowth. Measurements from dissociated cultures exposed to 75 mM ethanol immediately after plating showed a significant increase in the percentage of neurite-bearing cells after 8 and 24 h in vitro. Measurements of the area and perimeter of neuronal cell bodies in dissociated cell cultures showed that the cell bodies of ethanol-treated neurons were also larger than those of control neurons. Ethanol was also associated with significant increases in the total neuritic length per cell and in the length of the longest neurite in each cell. The mean number of neurite branches was also greater in the ethanol-treated neurons. Measurements from suspension cell cultures, in which dissociated cells were suspended overnight in the presence of 75 mM ethanol prior to plating, corroborated these results. These findings suggest that ethanol may have distinct effects on neurite initiation and outgrowth and branching. The cellular mechanisms involved and the functional significance of these effects are currently not known. The present results also indicated that high concentrations of ethanol (150-200 mM) and long periods of exposure (4-7 days) were required to produce toxic effects on neurons and glial cells in this system.