Figure 3.

Differential active lever responding for experiments 1 and 2. Difference in responding between cue‐induced reinstatement and last day of extinction. For clarity, the vehicle (Veh) groups have been collapsed across the two experiments. CS extinction resulted in decreased responding at CS‐induced reinstatement 24 h later in Veh‐treated animals only. CS‐elicited drug seeking at reinstatement was decreased in rats administered a PAM on the previous day, when compared with animals that had received a NAM. *P < 0.05.