(a) Diagram of the lentiviral vector used to express ΔFosB. Scale bar, 50 μm. For each mouse used, precise delivery of the virus was confirmed by visualizing ZsGreen1-expressing cells. (b) Validation of the ΔFosB-lentivirus. Western blot analysis of ΔFosB expression in HEK293FT cells 6 days after transduction of the control-LV (lentivirus) or ΔFosB-LV. Full-length blots are presented in Supplementary Figure 10. (c,d) mGluR5−/− mice that received ΔFosB LV in the NAc shell exhibited times spent in the interaction zone (c) and the corner zone (d) that were comparable to those of control LV-injected mGluR5+/+ mice (n = 4, 6, and 9 mice for WT-control LV, KO-control LV and KO-ΔFosB LV, respectively). Two-way RM ANOVA (in c, group × target interaction F (2,16) = 3.821, P = 0.044) followed by Bonferroni post hoc test for multiple comparisons; #P = 0.012, ##P = 0.006 compared with the WT-control LV in the presence of a target; †P = 0.046, ††P = 0.004 compared with the respective no-target conditions; §P = 0.028, §§P = 0.002 compared with the KO-control LV in the presence of a target. Data are expressed as the mean ± SEM.