Rats were trained in a two-lever nicotine discrimination assay. Data are the mean ± SE % responding on the nicotine lever during consecutive daily sessions with the 0.4 mg/kg s.c. nicotine training dose. Nic311 or control antibody was administered i.v. one day prior to session 1, and mecamylamine or saline was administered s.c. 15 minutes prior to each session. Dashed lines indicate criterion levels of performance for discrimination of the 0.4 mg/kg nicotine training dose. Significantly different from Control antibody+Saline, *p<0.05, ***p<0.001. Significantly different from Nic311+Saline, ##p<0.01, ###p<0.001. Reproduced from (LeSage et al., 2012).