Chronic consumption of alcohol by adult mice: effect on hippocampal cells and synapses.

For 4 months C57 black mice were fed a nutritionally complete diet containing 9% alcohol or isocaloric sucrose and killed then or after 4 months recovery on standard food pellets. The number of cells in a thin plastic section of hippocampus was unchanged in field CA1 by alcohol exposure but was reduced 9% during withdrawal from alcohol. Electron microscopy was used to count synapses among the basal dendrites and no significant change was found in any treatment group. The spine heads were measured and found to be smaller in the alcohol group than in the sucrose group; many of the spines (in the alcohol group) were too small to be visible with the light microscope.