Immediate and delayed voluntary ethanol effects on motor performance, learning and inhibition in rats

The effects of prolonged voluntary ethanol consumption on psychomotor perfo rmance, operant conditioning and inhibition were examined in adult male Wis tar rats. Animals were food deprived and alcohol or control solution was av ailable 1 h/day during 15 days, with free water for the rest of the day. Th en, rats were tested in a two-bottle paradigm (solution and water available ) for 1 h/day during 19 days, and subjects were tested daily for psychomoto r performance and operant conditioning immediately or 6 h after (delayed) t he solution access. Psychomotor performance was tested in an 80 degrees -in clined screen. Successive conditioning phases were: free shaping (FS), cont inuous reinforcement (CRF), operant extinction (EXT), successive discrimina tion (DIS) and two-stimuli test (TST). Alcohol consumption deteriorated psy chomotor performance and improved the animal's ability to learn simple asso ciations between stimuli and responses (free shaping and extinction), in im mediate and delayed groups. Finally, alcohol deteriorated behavioral inhibi tion (DIS and TST) tested immediately after drinking. Taken together, resul ts suggest that prolonged voluntary ethanol intake could induce permanent p sychomotor impairment and associative learning facilitation, and also an im pairment of the inhibition related to the intoxication state. (C) 2001 Else vier Science Inc. All rights reserved.