Adolescent and adult rats respond differently to nicotine and alcohol: motor activity and body temperature.

Alcohol and nicotine are the most widely abused drugs in the world. The use of these addictive drugs often begins in adolescence, however, little is known about the different impacts of nicotine and alcohol on adolescents versus adults. This study examined both the individual and combined effects of nicotine and alcohol on body temperature and locomotor activity in adolescent and adults rats. Rats were injected with saline (SC) + saline (IP), nicotine (SC) + saline (IP), alcohol (IP) + saline (SC) or alcohol (IP) + nicotine (SC). The dose selected for nicotine was 0.2 mg/kg and for alcohol 2.5 g/kg (16% v/v). For each age/treatment, 10-13 animals were used, with each animal receiving only one treatment. In regards to body temperature, both nicotine and alcohol caused a significant age x drug interaction. The combination of nicotine and alcohol caused greater drop in body temperature in adolescent than in adult rats. Neither of the two drugs, when given alone, caused differential effects in adolescents or adult rats, though both resulted in drop in body temperature. In terms of locomotor activity, the treatment that produced a significantly different effect between adolescents and adults was nicotine alone. Nicotine significantly decreased locomotor activity in adolescent compared to adult rats. These preliminary results suggest that adolescent rats may have an increased sensitivity to nicotine and alcohol, which may consequently impact their initial addiction to these two drugs.