Estudo dos efeitos do etanol sobre o encéfalo de ratos Wistar

Abstract

The consumption of alcohol by women of reproductive age associated with an unplanned pregnancy puts the pregnant woman at a greater risk of consuming alcohol during the early stages of pregnancy, when the symptoms are not yet evident, which can result in a variety of morphological, cognitive, and behavioral problems in the unborn child, being a serious public health problem. Therefore, we examined whether just one prenatal exposure to ethanol during the early stages of neuronal migration was able to affect the cytoarchitecture of the neocortex and the brain mass of the offspring. Ethanol injection was performed intraperitoneally in three doses (3g ethanol/kg body weight) at 8-hour intervals in pregnant female Wistar rats (180-230 g) twelve days after conception (E12) to model the alcohol exposure between 5-6 weeks of pregnancy in humans. To visualize the cells that migrated in this period, labeling with Bromodeoxyuridine (BrDU) was performed 24 hours after the first ethanol injection. Acute exposure caused the disruption of cell migration producing ectopia, heterotopia, and neuronal depopulation, which may characterize Fetal Alcohol Syndrome, but had no substantial impact on total brain volume. In summary, acute exposure restricted to early pregnancy had subtle effects on the brain mass of the offspring, but brought histological evidence of impaired neuronal migration, which contributes to cognitive impairments previously only described in chronic prenatal exposure to ethanol.