Figure 5. Antagonism of OX2r in the PVT prevents the escalation of sign-tracking behaviors and reduces the conditioned reinforcing properties of a reward-paired cue in sign-trackers, but has no effect in GTs.

Left panel, mean ± SEM for a) number of lever contacts in sign-trackers during Session 5, 6 and 7 of PavCA training. There was a significant Treatment x Session interaction (p = 0.004). Post-hoc analyses revealed that, compared to control rats (SAL), rats that received a single administration of the OX2r antagonist TCS-OX2-29 (TCS) before Session 6 showed a decrease in lever contacts (*p = 0.039 vs. SAL). c) Number of magazine entries in sign-trackers during Session 5, 6 and 7 of PavCA training. No effects were found for magazine entries in sign-trackers. b) number of lever contacts and d) magazine entries in goal-trackers during Session 5, 6 and 7 of PavCA training. There were no significant effects in goal trackers. N = 7 STs-SAL, 16 STs-TCS, 4 GTs-SAL, 7 GTs-TCS. Right panel, mean ± SEM for e) nosepokes, g) lever contacts, and i) incentive value index in STs. A significant reduction in lever contacts and incentive index was apparent in STs who received infusion of the OX2r antagonist TCS OX2 29 into the PVT (p<0.019 for both measures). For GTs, there was no significant effect of drug administration for f) nosepokes, h) lever contacts, or the j) incentive value index. N = 7 STs-SAL, 16 STs-TCS, 4 GTs-SAL, 7 GTs-TCS.