Chronic swim stress alters sensitivity to acute behavioral effects of ethanol in mice

Epidemiological data support a strong link between stress, stress-related disorders and risk for alcoholism. However, precisely how stress might impact sensitivity to the intoxicating effects of ethanol or the willingness to voluntary consume ethanol remains unclear. The present study assessed the effects of daily exposure to forced swim stress on subsequent sensitivity to the sedative/hypnotic, hypothermic, ataxic (measured using accelerating rotarod), and anxiolytic-like (measured using elevated plus-maze) effects of ethanol, and ethanol consumption and preference in a two-bottle choice paradigm, in male C57BL/6J mice. Stress effects on the sedative/hypnotic effects of the barbiturate pentobarbital were also tested. Results showed that chronic (fourteen days) but not acute (one or three days) swim stress significantly potentiated the sedative/hypnotic and hypothermic effects of 4 g/kg, but not 3 g/kg, ethanol. The sedative/hypnotic effects of pentobarbital were attenuated by chronic swim stress. Irrespective of chronicity, swim stress did not alter the ataxic or anxiolytic-like effects of ethanol, or alter ethanol self-administration either during or after stress. These data provide further evidence that stress alters the intoxicating effects of high doses of ethanol in a behaviorally selective manner.