(A) Experimental protocol for model establishment and analysis. (B) qPCR analysis of Ifitm3 expression in the hippocampi of the indicated mice (n = 4 mice/group). (C and D) Representative images of brain sections coimmunostained for p-STAT1 together with a neuronal marker (NeuN⁺) and quantification of positive cells in the CA1 region of the indicated groups (n = 4 mice/group). Scale bar: 20 μm. (E and F) Quantification of IBA-1⁺CD68⁺ phagocytes (E) and CD68 staining intensity (F) in the hippocampi of the indicated groups (n = 5 mice/group). (G and H) Representative 3D reconstruction and quantification of engulfed PSD-95⁺ puncta (green) in CD68⁺ lysosomes (red) in the CA1 region of the indicated groups (n = 15–17 cells/group from 5 mice). Scale bar: 2 μm. (I and J) Immunostaining and quantification of presynaptic (SYP, red) and postsynaptic (PSD-95, green) proteins in hippocampal sections from the indicated mice (n = 5 mice/group, with an average of 3–4 slices per mouse). Scale bar: 10 μm. (K–M) The depression-like behavior of the indicated mice was assessed. The SPT (K), TST (L), and FST (M) were performed 3 weeks after antibody treatment (n = 8 mice/group). (N) Quantification of Golgi-stained dendritic spines of dentate gyrus granule neurons in MSCT (or MSCT plus IFN-γ–treated) MRL/lpr mice (n = 5 mice/group). (O and P) Depression-like behavior of the indicated mice was assessed via the TST (O) and the FST (P) (n = 8–10 mice/group). The data are presented as mean ± SEM. *P < 0.05; **P < 0.01; ***P < 0.001, determined using 1-way ANOVA followed by Tukey’s post hoc test (B, D, H and J), or 2-tailed unpaired t test (E, F and K–P). IOD, integrated optical density; SPT, sucrose preference test; TST, tail suspension test; FST, forced swim test. See also Supplemental Figure 10.