Paternal alcohol exposure: paradoxical effect in mice and rats

Male mice consumed liquid alcohol diets containing 25%, 10% or 0% ethanol-derived calories (EDC). Animals receiving the 10 and 0% EDC diets were pair fed to those consuming the 25% EDC diet. After 7 or 14 weeks of consumption, males were bred to non-treated females. Offspring were tested for swimming behavior at 75 days of age. Offspring sired by alcohol-consuming males were more immobile regardless of duration of paternal alcohol consumption or housing conditions (group or isolated). Imipramine (5, 15 mg/kg) reversed this effect such that after drug treatment, alcohol-sired offspring were less immobile than controls. Propranolol (1, 3 mg/kg) eliminated the group differences. Yohimbine (1, 10 mg/kg) significantly increased immobility in all groups but did not reverse the effects of paternal alcohol consumption. Metergoline (1 mg/kg) increased immobility in all groups but did not reverse the effects of paternal alcohol exposure. When rat offspring of alcohol-consuming fathers were tested, their swimming behavior was opposite to that of mice (i.e., rats were less immobile). However, as observed in mice, the effect was reversed by imipramine. These results extend the evidence for paternally mediated behavioral mutagenesis. They also indicate that the direction of induced changes are species dependent and that some of these effects, regardless of direction of change, are mediated by neurochemical changes sensitive to imipramine.