The effects of repeated doses of ethanol on exploration and its habituation

The effects of ethanol (0.8-2.4 g/kg) on exploratory behavior and its habituation were investigated by testing DBA/2 mice in a holeboard apparatus. Mice familiar with the holeboard had lower levels of exploration than animals with no previous experience in the apparatus. If the animals received ethanol during their first exposure to the holeboard they did not show the same degree of habituation. Ethanol (0.8 g/kg) increased the exploration of animals naive to the holeboard, but failed significantly to increase the exploration of animals familiar with the apparatus. An increase in locomotor activity was observed following treatment with ethanol (2.4 g/kg). This was potentiated if animals received a single treatment with ethanol 3 days earlier, but only if they were tested in the apparatus following the initial treatment. These results have important implications for the design of experiments investigating tolerance and sensitization to ethanol's effects on locomotor activity and exploration.