Voluntary Ethanol Drinking Increases Locomotor Activity in Alcohol-preferring AA Rats

This study explored, first, whether voluntary ethanol consumption produces locomotor stimulation in ethanol-preferring AA rats. Rats had continual access to water but access to a second bottle containing 10% ethanol, 0.1% saccharin, or water only for 10 min/day. Locomotor activity was significantly increased after the drinking in the ethanol group. Second, we compared the locomotor responses of AA and ANA (ethanol-avoiding) rats to IP ethanol (0.6 and 1.0 g/kg). Rats habituated to test cages showed no effects, but on a modified open field novel to animals there was a short increase in activity without any rat line difference. This activity increase might have resulted from a weak anxiolytic action of ethanol, indicated by the finding in the elevated plus-maze where IP ethanol (1.0 g/kg) increased the number of crosses from a closed arm to another in both AA and ANA rats. The results suggest that ethanol has reinforcing effects in AA rats when drunk but not when injected IP.