Fig. 4

NMDARs transiently mediate the expression of cued NAc activity and approach behavior. a Task. ITI: intertrial interval. b Microinjection schedule. c For the moderate training group, performance index in S+ (solid) and S− trials (empty squares) before and after saline (VEH, blue) or AP5 (red) microinjection (mean ± SEM). The gray rectangle represents the microinjection period. In S+ trials, AP5-treated subjects performed worse than subjects in the control group in every post-injection 30 min bin (***p < 0.001; **p < 0.01; t test). d Firing rate (FR; mean ± SEM) in Z scores (Z sc.) around S+ onset in the moderate training group before (gray) or after injection of saline (blue, left) or AP5 (red, right). Insets show activity 100–400 ms after S+ before (pre) or after (post) injection. Boxes show the interquartile range (box height), mean (black line), and median (red/blue line). Activity was unaffected by saline (p = 0.64), but reduced by AP5 injections (***p < 0.001, Wilcoxon). e, f Same as in c, d, but for animals in the extended training group. In this group, performance was not disrupted by AP5 injections (p > 0.05, t test). S+-evoked activity was also unaffected by saline (p = 1) or AP5 injections (p = 0.2, Wilcoxon)