Effect of prenatal exposure to ethanol on adult ethanol preference and response to zimelidine in rats.

The effects of prenatal ethanol (ETOH) exposure (2.8-3.5 g/kg per day) on subsequent adult ETOH preference and on ETOH consumption after treatment with zimelidine, a serotonin uptake inhibitor, were investigated. Pregnant rats were exposed to an ETOH/saccharin solution in the first, second, third, all three, or none, of the trimesters of the gestation period. As adults, the offspring were subjected to a 40-day screening procedure to determine ETOH preference (greater than 50% of total daily fluid consumption) over water (experiment 1). Only animals which preferred ETOH were included in experiment 2, in which they received either five daily injections of zimelidine (20 mg/kg) or comparable volumes of Ringer's solution. Results indicated that although there were no differences between groups in terms of ETOH preference, a significant difference was evident in ETOH intake after zimelidine treatment. All groups of rats showed a significant decrease in ETOH intake from baseline levels when given zimelidine. However, only rats prenatally exposed to ETOH in the first trimester demonstrated a significant decrease in ETOH drinking when compared to controls. These results suggest that early prenatal ETOH exposure, even in moderate doses, may induce central neurochemical alterations that are salient enough to be detected in adulthood.