| a, Cannula placement and Hoechst33342 dye infusions into the vDG. Image adapted from Allen Institute Brain Explorer 2 (http://mouse.brain-map.org/static/brainexplorer). b, Experimental design for subthreshold defeat. TMX, tamoxifen; CNO, clozapine-N-oxide. c, Silencing abGCs decreases social interaction time (Interaction F1,33=40.98, ***P<0.001; genotype F1,33=13.46, ***P=0.0009; stress F1,33=17.7, ***P=0.0002; post-hoc test, ***P<0.001; N=9, 9, 9, 10). d, Silencing abGCs decreases open field center exploration (Interaction F1,33=1.4, P=0.25; genotype F1,33=4.2, *P =0.048; stress F1,33=6.9, *P =0.01; planned comparison t-test, ##P=0.009; N=9, 9, 9, 10). e, Quantification of c-fos+ cells (Interaction F11,176=2.1, *P=0.02; genotype F1,16=1.2, P=0.28; dorsal-ventral F11,176=2.2, *P=0.01; post-hoc test, section 10: **P=0.008, section 11: **P=0.002, NCRE−=8, NCRE+=10). D-V; dorsal-ventral axis. f, Schematic and g, representative responses of mature granule cells (mGCs) to perforant path (PP) stimulation in vitro. Scale bars: 2 mV, 100 ms. h, Area under the curve (AUC) quantification of evoked responses (paired t-test, *P=0.02; N=7). Error bars, ± s.e.m.