FIGURE 3.

Extinction of operant responding for toluene vapor. During extinction training, a nose poke in the active hole had no consequence (i.e., did not trigger toluene delivery or conditioned cues). (A) Number of active (ANP) and inactive nose pokes (INP) for Air SA and Tol SA rats during extinction training. SA is average ANP and INP during last week of self-administration; ^^p < 0.01 Tol ANP EXT vs. Tol SA, ^∗∗∗p < 0.001 Tol ANP EXT vs. Tol INP EXT, Sidak’s post hoc. (B) Number of ANPs that would trigger a toluene vapor delivery under normal SA conditions. SA is average number of vapor deliveries during last week of self-administration; ^p < 0.05, Tol EXT vs. Tol SA, ^∗∗∗p < 0.001 Tol vs. Air, Sidak’s post hoc. All data are mean + SEM. Air N = 6, Tol N = 6.