CTGF knockdown in the right mPFC prevents chronic social defeat stress-induced increases in social avoidance. a The L/R expression ratio of Ctgf in the mPFC. The L/R ratio of susceptible mice is significantly less than those of control and resilient mice (H = 9.620, df = 2, **p = 0.008, Kruskal–Wallis One Way Analysis of Variance on Ranks; between control and susceptible, *p < 0.05, between control and resilient, p > 0.05. between resilient and susceptible, *p < 0.05, Post-hoc analysis with Turkey test). b Upper panel: A representative blot of CTGF protein expression. Lower panel: CTGF protein expression in the mPFC, presented as a bar graph. The CTGF level is significantly different between the left and right mPFC in susceptible mice (For group \(\times\) laterality F(2, 38) = 4.489, *p = 0.018; **p = 0.002, laterality within resilient p = 0.357; two-way ANOVA with post-hoc analysis). The CTGF expression in resilient and susceptible mice showed a significant difference compare to control (within left mPFC, control and resilient, **p < 0.001, resilient and susceptible, *p = 0.016; within right mPFC, control and resilient, *p = 0.025, control and susceptible, **p < 0.001; two-way ANOVA with post-hoc analysis). c Upper panel: Scheme of injection to the mPFC. Middle panel: Representative immunohistochemistry image showing shRNA-mediated CTGF knockdown. Scale bar = 200 μm. Lower panel: Experimental timescale of CTGF shRNA expression followed by chronic social defeat stress and behavioral analysis. d Upper panel: Confirmation of CTGF knockdown (KO) by Western blot analysis. Lower panel: Quantitative analysis of CTGF knockdown, expressed as the ratio CTGF/β-actin in arbitrary units. Image quantification and analysis was done using the ImageJ program (*p = 0.0464 for scrambled [Control] vs. KO, t-test, t4 = 2.850; Control, n = 3; KO, n = 3). e Interaction times with CD-1 mice under non-stressed (Con) and stressed (+ Stress) conditions are presented as means ± standard deviation. Comparison of time spent in the interaction zone by non-stressed (black bar) and stressed (red bar) mice injected in both hemispheres of the mPFC with scrambled shRNA. Open bar, time spent in the interaction zone without a target; closed bar, time spent in the interaction zone with a target present (For stress \(\times\) target, F(1, 28) = 5.126, *p = 0.032, two-way RM ANOVA; within non-stressed, effect of target, **p = 0.002; within stressed, effect of target, p = 0.709; within non-target, effect of stress, p = 0.739, within target, effect of stress, *p = 0.019, Post-hoc analysis with Holm-Sidak method). f Comparison of time spent in the interaction zone by non-stressed and stressed mice with CTGF shRNA expression in the left mPFC and scrambled shRNA in the right hemisphere (For stress \(\times\) target, F(1, 28) = 4.478, *p = 0.043, two-way RM ANOVA; within non-stressed, effect of target, **p < 0.001; within stressed, effect of target, p = 0.080; within non-target, effect of stress, p = 0.949, within target, effect of stress, *p = 0.014, Post-hoc analysis with Holm-Sidak method). g Comparison of time spent in the interaction zone by non-stressed and stressed mice with CTGF shRNA expression in the right mPFC and scrambled shRNA in the left hemisphere (For target F(1, 24) = 58.986, **p < 0.001, stress \(\times\) target, F(1, 24) = 2.480, p = 0.128, two-way RM ANOVA; within non-stressed, effect of target, **p < 0.001; within stressed, effect of target, **p < 0.001; Post-hoc analysis with Holm-Sidak method). h Left: Representative heatmaps of normalized time spent by mice in the indicated locations without (No Target) and with (Target) a CD-1 target mouse. Non-stressed mice (Non) and stressed mice (Stress) that had been injected in both hemispheres of the mPFC with scrambled shRNA (Control). Center: Representative heatmaps of normalized time spent in the indicated locations by mice with CTGF shRNA expression in the left mPFC and scrambled shRNA in the right mPFC (Left KD). Right: Representative heatmaps of normalized time spent in the indicated locations by mice with CTGF shRNA expression in the right mPFC and scrambled shRNA in the left hemisphere (Right KD)