Panels A-B: Mean (±SEM) total food intake (panel A), time to first pellet (sec; panel B), throughout daily 2 h experimental sessions, following injections of three doses of nicotine and EC liquid. *p < 0.05, ** p < 0.01 difference between saline and nicotine at the indicated dose. #p < 0.05, ##p < 0.01 difference between saline and EC liquid at the indicated dose. Panel C: Mean (±SEM) running rates, following injections of saline, nicotine, and EC liquid. **p < 0.01 difference between saline and nicotine at the indicated dose. ##p < 0.01 difference between saline and EC liquid at the indicated dose. Panel D: mean (±SEM) total number of pellets consumed during 10-minute intervals throughout daily 2 h experimental sessions, following injections of two doses of nicotine and EC liquid. *p < 0.05 difference from saline for all drugs and doses tested. ##p < 0.01 difference from saline for 1.00 mg/kg nicotine only.