Nina Kaminen-Ahola
Group Leader

Department of Medical
Genetics

P.O. Box 63
(Haartmaninkatu 8)
00014 University of Helsinki
Finland

nina.kaminen[at]helsinki.fi

+358 (0)50 4482768

Mouse model for alcohol exposure during early pregnancy

Alcohol exposure during early pregnancy alters the epigenome, gene function and structure of the hippocampus in mouse offspring

This study focused on the hippocampus, a structure in the brain essential to memory and learning. It is known to be sensitive to the effects of alcohol. In this study, early alcohol exposure altered the epigenome that regulates gene function and the function of several genes in the hippocampi of young mouse pups. In addition, alcohol also caused similar changes in gene function in two other tissues, bone marrow and the olfactory epithelium. These results support our hypothesis that alcohol can change gene regulation permanently already at a very early stage. Early epigenetic changes that alter gene regulation could be considered as biomarkers and would offer a new tool for the challenging diagnostics of alcohol-induced developmental disorders.

Changes in brain structure
Alcohol-induced changes were seen in the brain structures of the adult offspring: the hippocampi, olfactory bulbs and cerebral ventricles. Surprisingly, the most significant discovery was alcohol-induced enlargement of the left hippocampus. Could this be the associated with unexpected results in behavioural tests (Sanchez Vega et al. 2013)? According to these tests, pups exposed to alcohol were not only more active, but performed better in tests measuring spatial or place-related memory. Perhaps the larger hippocampus could explain the improved spatial memory observed in the mouse model.

The results concerning the enlarged hippocampus and better spatial memory are surprising. Numerous studies have shown that prenatal ethanol exposure impairs offspring’s spatial memory. In this study, however, the alcohol exposure takes place very early. In addition to dose, timing of ethanol exposure seems to be significant for the function of the hippocampus.