Effects of chronic alcohol exposure on the morphometric development of medial preoptic area neurons of the male mouse.

We have performed a karyometric study of the medial preoptic area of male mice from mothers that ingested chronically a solution of 20% of ethanol added to the drinking water. Pups then were exposed prenatally to alcohol. After parturition, pups were also exposed to alcohol, first through their mother's milk and after weaning by direct ingestion of the same solution of 20% of alcohol until the day of sacrifice. Animals were sacrificed at the 25th, 35th, 45th, 55th and 100th day and the results compared with those obtained in another group of control animals, sacrificed at the same ages. Chronic alcohol exposure reduces the studied nuclear sizes (perimeter, area and maximum diameter) in adult animals of 100 days of life, but does not produce significative changes in nuclear sizes of younger animals. However, nuclear shape, another of the nuclear parameters analysed, did show significative alterations in relation with the puberal age. These morphometric effects could be due to the reduction of plasmatic testosterone levels produced by alcohol and/or to a direct toxic effect of the alcohol on central nervous system neurons.