The effects of prenatal alcohol exposure on odor associative learning in rats

Alcohol was administered to pregnant females via a liquid diet that contained either 35% ethanol-derived calories (35% EDC) or 0% EDC on gestation days 6-20. An ad lib lab chow group (LC) was also included. In Experiment 1, odor-aversion learning was examined in 10-day-old offspring. While both the 0% EDC and LC groups displayed odor aversions, the 35% EDC offspring did not. In Experiment 2, learning was assessed in an appetitive paradigm in three-day-old offspring. Once again, the 35% EDC offspring showed no evidence of learning. Experiment 3 examined odor-aversion learning in adults. Both alcohol-exposed offspring and controls learned the odor association equally well. These findings suggest that odor associative learning is a sensitive indicator for alcohol-related learning deficits in rat pups although these deficits may dissipate as the offspring matures. Since odor associations play a critical role in neonatal behaviors, these deficits may help explain other behavioral anomalies noted following prenatal alcohol exposure.