Genetic Factors Involved in the Effects of Developmental Low-Level Alcohol Induced Behavioral Alterations in Rats

Abstract

Behavioral and neurochemical effects of perinatal 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. In an elevated zero-maze model of anxiety, sucrose-exposed sP rats (sP-S): (i) spent significantly less time on the open arms (TO); (ii) exhibited a significantly lower number of head dips (HDIPS); and (iii) showed a higher number of stretched attend-postures (SAP) than sucrose-exposed sNP rats (sNP-S) at 90 and 180 days of age. The two rat lines displayed different emotional reactivity in response to alcohol exposure. Subtle differences in sexual behavior and ultrasonic emission (latency to the first intromission and to the first 50 kHz call) were observed between sP-S and sNP-S rats. sP-alcohol exposed (sP-A) offspring exhibited a higher latency to the first intromission than sNP-alcohol (sNP-A) treated rats. Moreover, a lower number of sP-A rats exhibited both intromission and ejaculation with respect to sNP-A animals. sP-S rats were significantly slower in recover of the righting reflex than sNP-S animals after a challenge dose of alcohol (3 g/kg, i.p.). Perinatal alcohol did not affect either onset or duration of sleep time in either line. Neurochemical experiments have shown that perinatal alcohol did not influence basal dopamine levels or amphetamine-induced dopamine increase in the prefrontal cortex of either sP or sNP offspring. These results, showing an endpoint-specific differential sensitivity of sP and sNP lines to perinatal low alcohol exposure, indicate that genetic factors could be responsible for selective susceptibility to behavioral alterations induced by developmental treatment with this drug of abuse.