Paula C Bianchi, Fabio C Cruz, Paulo E Carneiro-de-Oliveira, Tarciso T Miguel, Marcelo T Marin, Ricardo L Nunes-de-Souza, Cleopatra S Planeta and Rodrigo M Leão
Among drugs of abuse, nicotine and alcohol are the most consumed in the world, and are often co-abused. Evidence has shown that nicotine enhances the consumption and subjective effects of ethanol. How nicotine increases alcohol consumption is an interesting question that is still left unanswered. We assessed whether repeated treatment with nicotine during adolescence or adulthood could increase operant alcohol selfadministration. Male adolescent and adult rats (postnatal day [PND] 28 and 60, respectively) were injected with nicotine (1.0 mg/kg, subcutaneously [s.c.], three times a day for 10 days). During this period, the control group received saline injections (0.1 ml/kg; s.c). On PND 72, adolescent and adult rats pretreated with nicotine were subjected to ethanol self-administration procedures. Alcohol oral self-administration patterns were evaluated using a progressive ratio schedule of reinforcement and 24-hour unlimited access to ethanol. Our results showed that nicotine pretreatment in adult rats increases the motivation for alcohol consumption. However, nicotine exposure during adolescence does not affect alcohol-consuming behaviors in adulthood.