Alcohol tolerance in rats submitted to different periods of chronic and acute ethanol intake

social, family and psychological problems in our society. Traffic accidents are the main cause of death among young people and many of these have been caused by high alcohol consumption. Impaired judgment and increased reaction time are most often cited as the causes of alcohol-related traffic accidents (Gómez Fraguela, Luengo Martín and Romero Triñanes, 2002; Naranjo and Bremner, 1993). Laboratory psychopharmacologic studies indicate that doses of ethanol up to 1 g/Kg are associated with a general slowing down of psychomotor and cognitive performance such as reduced information-processing capacity or impaired tracking performance in real and simulated driving tasks (Hindmarch, Kerr and Sherwood, 1991; Maylor and Rabbitt, 1993). Nowadays, young people drink alcohol at an early age and consume large amounts in very short periods of time. Most people begin drinking in adolescence and many recent studies have indicated that adolescence may represent a period of development of great sensitivity to ethanol and that, in this period, behavioral and neuronal aspects are more affected than in adulthood (Rodríguez Franco, Padilla Muñoz, Caballero and Rodríguez, 2002; De Bellis et al., 2000; Acheson, Richardson and Swartzwelder, 1999; Pyapali, Turner, Wilson and Swartzwelder, 1999; Swartzwelder, Richardson, Markwiese-Foerch, Wilson and Little, 1998; Markwiese, Acheson, Levin, Wilson and Swartzwelder, 1998; Swartzwelder, Wilson and Tayyeb, 1995). One component of alcoholism that is commonly studied is the development of alcohol tolerance after chronic or acute alcohol consumption. According to DSM-IV (American Psychiatryc Association, 1994), alcohol tolerance is the decrease in ethanol effects with regular consumption of the same dose or the necessity to drink more alcohol to experience the same effects. However, the development of tolerance is not uniform and the effects of ethanol decrease to different extents and in different time periods. Previous studies in adult rats have shown that tolerance to the effect of ethanol on body temperature develops prior to tolerance to motorimpairing effects (Pohorecky, Brick and Carpenter, 1986). One of the characteristic response to administration of moderate to high doses of ethanol is a decrease in body temperature. EthanolAlcohol tolerance in rats submitted to different periods of chronic and acute ethanol intake