Sardinian alcohol-preferring rats: a genetic animal model of anxiety.

The present study was designed to assess the anxiety profile of the selectively bred alcohol-preferring sP and alcohol-nonpreferring sNP rats. Rats were offered either water (ethanol-naive rats) or a free choice of 10% (v/v) ethanol and water (ethanol-experienced rats) for 14 consecutive days prior to the test. Spontaneous exploration of an elevated plus maze was used as a behavioral measure of anxiety. Ethanol-naive sP rats spent less time in and made fewer entries into the open arms of the maze than ethanol-naive sNP rats. These results suggest a higher innate degree of anxiety in sP than in sNP rats. Moreover, time spent in and number of entries into the open arms of the maze were higher in ethanol-experienced than in ethanol-naive sP rats. This finding suggests that ethanol consumed voluntarily produces anxiolytic effects in sP rats. The results of the present study are discussed in terms of (a) anxiety as a genetic trait related to ethanol-preference in sP rats and (b) self-medication of anxiety as a possible factor promoting voluntary ethanol consumption in sP rats.