Side preference behavior in rats exposed to alcohol prenatally.

Exploration and side preference in a two-hole nose-poke apparatus were examined in 28 to 31-day-old Long Evans rats from three prenatal treatment groups: prenatal alcohol exposed (35% ethanol-derived calories, 35% EDC), nutritional control (0% ethanol-derived calories, 0% EDC) or standard control (lab chow, LC). Rats prenatally exposed to alcohol had significantly more total pokes than the two control groups, who did not differ, replicating the previous demonstration of increased exploration in this age group. All three groups differed significantly in their side preference behavior over the time course of the test session. However, both control groups maintained their preferred side whereas the 35% EDC group alternated side choice over the test session. The three groups also differed in overall degree of side preference; the LC group had the greatest degree of side preference and the 35% EDC group the lowest, with the 0% EDC group intermediary. These results suggest an altered development of cerebral laterality in offspring exposed to alcohol during gestation, and that the effect of alcohol interacts with nutritional variables.