CHRONIC PRENATAL ETHANOL EXPOSURE DOES NOT AFFECT THE EXPRESSION OF SELECTED GENES IN RAT-BRAIN DEVELOPMENT

To investigate possible mechanisms contributing to the teratogenic eff ects of ethanol on the nervous system, we examined the effects of in u tero exposure to ethanol on gene expression in the postnatal brain. Pr egnant rats were exposed to ethanol by constant inhalation of ethanol vapor during gestational days 8-21, generating a mean blood alcohol le vel of approximately 150 mg/100 ml during the last week of gestation. Particular care was given to ensure proper nutrition and weight gain i n both control and EtOH-treated groups. At different times after birth , the brains of pups from ethanol-treated dams and from a parallel ser ies of untreated dams were dissected into major regions. Cytoplasmic R NA was assayed for different mRNAs encoding proteins representative of both glial and neuronal cell types, by Northern blot and solution hyb ridization. In situ hybridization was performed with Talpha-1 tubulin and PLP. There were no significant differences between pups from ethan ol-treated and control dams in the amount of mRNAs encoding the myelin protein proteolipid protein (PLP), the astrocyte glial fibrillary aci dic protein (GFAP), the neurally enriched Talpha-1 isotype of alpha-tu bulin, the nerve terminal components synaptophysin p38 and SNAP 25. Th e mRNA encoding the alpha1-subunit of the receptor for gamma-amino but yric acid (GABA) was slightly decreased in expression in the hindbrain but not cortex of pups from EtOH-treated dams. These results suggest that, when weight gain is controlled, chronic exposure of rats to etha nol during the last 2 weeks of gestation has little influence on the p ostnatal expression of these cell type specific genes.