Fig. 1.

(A) A cartooned version of the standard discriminated goal-tracking protocol used in the laboratory with 0.4 mg (base)/kg nicotine as the CS. As indicated in this graphic, the measure of conditioning comes from the time before the first sucrose delivery on nicotine sessions or an equivalent time in saline session. Given that this time varies across sessions, we use rate of dipper entries per second as the primary dependent measure. (B) Acquisition data from rats in Experiment 5 (transfer of extinction with varenicline) from Reichel et al. (2010); these data were not reported in that paper.