Nicotine administration increases 20% ethanol operant self-administration. (A.) Nicotine (0.8 mg/kg, s.c.), but not vehicle (saline), administered 15 minutes prior to the session significantly increases ethanol intake. The values are expressed as mean ethanol intake g/kg/60min ± SEM (two-way ANOVA followed by Newman-Keuls post hoc test). * p< 0.05, ** p<0.01, *** p<0.001, n=12 for the nicotine group and n=11 for the vehicle group.