Stress induces behavioral sensitization, increases nicotine-seeking behavior and leads to a decrease of CREB in the nucleus accumbens

► We examined the effects of variable stress on nicotine behavioral sensitization. ► Molecular assays to evaluate CREB and ERK activity. ► Effects of variable stress on nicotine-seeking behavior. ► Stress caused a sensitized motor response and decrease CREB in the nucleus accumbens. ► Stress exposure caused an increase in the break point and nicotine intake.