Effects of short-term prenatal alcohol exposure on maze, activity, and olfactory orientation performance in rats.

Long-Evans rats were gavaged twice each day with 4 g/kg/day, of ethanol on days 10-14 of gestation. Ethanol and control offspring were reared by untreated surrogate dams to minimize possible postnatal maternal treatment influences. Ethanol-exposed offspring exhibited delayed olfactory orientation (discrimination) to home cage scent and delayed lower incisor eruption compared to pair-fed or ad lib fed controls. After weaning, the ethanol offspring exhibited increased open-field section entries, particularly of centrally located sections, and facilitated swimming performance in a water maze. Ethanol exposure significantly decreased weight gain and increased postnatal, but not prenatal, mortality in the progeny. The female ethanol offspring also showed delayed vaginal patency development. This was due to large delays in vaginal development in a small number of individuals in this group; no such lag was seen in any members of either control group. The data confirm that short-term prenatal alcohol exposure can produce many of the behavioral effects previously reported when alcohol is administered throughout most or all of pregnancy.