Panel A shows the mean dipper entry rates (±1 S.E.M.) of nafadotride substitution for each nicotine training group. Panel B shows the mean beam break (activity) rates (±1 S.E.M.) of nafadotride substitution for each nicotine training group. The number of rats for nafadotride substitution was 7, 7, and 6 for the 0.1, 0.2, and 0.4 mg/kg groups, respectively. For both panels, significant differences and baseline means are reported in the text.