Neurofunctional Effects of Developmental Alcohol Exposure in Alcohol-Preferring and Alcohol-Nonpreferring Rats

The neurofunctional effects of developmental alcohol exposure (3% v/v solution from day 15 of gestation to day 7 after parturition) have been investigated in Sardinian alcohol-preferring (sP) and alcohol-nonpreferring (sNP) rat lines, selectively bred for opposite alcohol preference and consumption. Alcohol exposure significantly decreased the rate of ultrasonic emission in sP male pups; whereas, it did not affect this indicator of emotional reactivity in sNP animals. Perinatal alcohol intake did not influence either learning of an active avoidance task or hippocampal long-term potentiation in both offspring lines. Significant differences in time spent exploring novel objects were observed between control sP and sNP rats subjected to the novel exploration object test. Alcohol exposed sP rats, but not alcohol exposed sNP rats, apparently lost the capacity to discriminate between the novel and the familiar object, even though this difference is difficult to interpret because of the large differences in the respective responses to the novel objects. Neurochemical experiments have shown that basal levels of dopamine (DA) and homovanillic acid (HVA) were significantly higher in the nucleus accumbens (NAC) of sP rats with respect to sNP animals. Perinatal alcohol did not affect basal DA and HVA concentrations or amphetamine-induced DA increase and HVA decrease in the NAC of either sP or sNP offspring. These results suggest that subtle behavioral alterations induced by developmental exposure to low doses of alcohol, which do not cause malformations and/or overt neurotoxicity, may be associated with genetic factors, although not necessarily those responsible for differences in alcohol preference.