a Schematic diagram showing the experimental strategy for Arg1 overexpression. AAV-DIO-Arg1-GFP was stereotactic injected into hippocampus DG of CX3CR1-creER mice. b Timeline of experiment. Mice were analyzed 5 weeks after AAV injection. c Representative micrographs of Arg1 overexpression characteristically in hippocampal microglia. d Total distance of the adult offspring in open field test. n = 10 per group; F3, 36 = 5.471, P < 0.05, one-way ANOVA. e Similar response to 70 dB background noise in the three group. f PPI was impaired in Poly offspring compared with Ctrl offspring and ameliorated in Poly+AAV-DIO-Arg1-GFP offspring. n = 10 mice per group. Group: F3, 36 = 8.963, P < 0.05; Pepulse intensity: F2, 72 = 18.61, P < 0.001; Group × Prepulse intensity: F6, 72 = 0.554, P > 0.05, two-way ANOVA with repeated measures. g Increased latency for Poly offspring to locate the hidden platform, compared to Ctrl offspring, and decreased in Poly+AAV-DIO-Arg1-GFP offspring. n = 10 mice per group. Group: F3, 36 = 4.873, p < 0.05; Day: F3, 108 = 13.719, p < 0.01; Group × day: F9, 108 = 2.824, p > 0.05, two-way ANOVA with repeated measures. h In the probe trial, data are presented as percent time and percent distance in the target quadrant. n = 10 mice per group, F3, 36 = 3.568, P < 0.05, one-way ANOVA. For Fig. g *p < 0.05, **p < 0.01 for Poly offspring vs. Ctrl offspring; #p < 0.05 for Poly+AAV-DIO-Arg1-GFP offspring vs. Poly offspring. Values are the mean ± SEM. *p < 0.05, **p < 0.01, n.s., not significant.