Early developmental alcohol exposure alters the motor activating effects of alcohol during adolescence

CHINER, F.; FERNANDEZ M.; DI DOI, P.; HAEGER, P.; PAUTASSI R.M.

Puerto Varas

Congreso; VIII International meeting of the Latinamerican Society of Research on Alcoholism; 2017

Latinamerican Society of Research on Alcoholism

It is important to analyze the motivational effects of early exposure to alcohol. The consumption of alcohol by the pregnant mother, even in moderate quantities, increases the possibilities of problematic consumption in the offspring. The present work analyzed (Experiment 1) basal and alcohol-induced motor activity, a proxy of the appetitive motivational effects of this drug, in adolescent Wistar rats (females only) derived from mothers exposed to alcohol [10%, mixed in sucralose (64mg/l)] or sucralose only (control group), as the sole fluid for 22 h/day (plus a supplement of 2h/day of only water) throughout gestation and until postnatal day 7 (PD7). A second experiment analyzed basal or ethanol-induced activity in adult, Sprague Dawley male rats that had been or not exposed to alcohol, as described for Experiment 1. Experiment 1: the dams consumed an average of 6.0-7.0 g/kg/d of ethanol, approximately. On PDs 32 and 34 the adolescent offspring was habituated to an open field. On PDs 36, 38, 43 and 45, the animals received an administration of ethanol (0.0 or 2.0 g/kg, i.p.) and immediately after they were evaluated in an open field (OF) for 15 minutes. The results indicated the absence of significant differences between the groups during the habituation sessions. The rats of the prenatal control group did not exhibit motor activation by alcohol, in any of the tests. On the contrary, the rats derived from mothers exposed to alcohol showed a significant increase in motor activity after receiving alcohol, compared to control peers that had received vehicle. This stimulant effect of alcohol was particularly noticeable in the first part of the test and it was fairly similar across testing days. Experiment 2: On PD 80 the male offspring received an administration of ethanol (0.0 or 1.0 g/kg, i.p.) and immediately after they were evaluated in an OF for 10 minutes. The results indicated similar number of crossings and time in the center of the OF, across treatments. Animals exposed to ethanol, however, exhibited greater number of rearings ? an indicator of exploratory activity -- than control counterparts. These results indicate that exposure to alcohol during the prenatal stage (and during the first days of the lactation) sensitizes the stimulant, motor activating, effects of alcohol, as measured during adolescence. Some effects of this developmental alcohol exposure persisted until adulthood, when adult rats with a history of early alcohol exposure exhibited alterations in ethanol-induced exploratory activity. Heightened sensibility to the rewarding effects of alcohol might be one of the mechanisms that underlie the increased risk for alcohol problems, exhibited by those that have been exposed to the drug early in life.