Moderate Alcohol Intake: Behavioral and Neurochemical Correlates in Rats

A debate is open in the literature concerning the safety of low (dietary) versus high (intoxicating or addicting) alcohol consumption. Epidemiological data do indeed suggest that moderate ethanol intake may have beneficial effects, at least at cardiovascular level. On the other hand there are few data on the effect of low doses ethanol at brain level and few experimental models to investigate it, in spite of a vast literature on the addicting mechanisms. In the last years we have addressed this question by investigating behavioral and neurochemical parameters in rats consuming low ethanol doses, not producing tolerance and dependence, thus mimicking balanced dietary intake of ethanol. Ethanol exposure (3% vol/vol in drinking water for 8 weeks) ameliorates emotional reactivity, evaluated as decrease in ultrasonic calls, and improves learning in animals undergoing a two-way avoidance task. The concomitant measure of neurochemical parameters indicates plastic changes in receptor (dopamine) and post-receptor (protein kinase C) mechanisms. These changes are in some cases qualitatively different from those observed with intoxicating ethanol doses. This model may be useful for the further characterization of the beneficial versus detrimental effect of moderate ethanol consumption at brain level.