Fig. 2

Influence of time interval on the preventive effect of MPL on CSDS-induced anxiety-like behaviors in mice. A Timeline for the evaluation of the influence of time interval on the preventive effect of a single MPL pre-injection on CSDS-induced anxiety-like behaviors in mice. B–D Quantitative analysis showing the influence of 1, 5, or 10 days of interval between the single MPL injection (400 μg/kg) and stress exposure on the time spent in open arms (B), the number of entries into open arms (C), and the number of entries into total arms (D) in the EPM test in mice treated with or without CSDS and/or MPL (n = 10, *p < 0.05 or **p < 0.01 vs. vehicle; ##p < 0.01 vs. vehicle + CSDS). E, F Quantitative analysis showing the influence of 1, 5, or 10 days of interval between the single MPL injection (400 μg/kg) and stress exposure on the time spent in lit side (E) and the number of total transitions (F) in both lit and dark side in the LDT in mice treated with or without CSDS and/or MPL (n = 10, *p < 0.05 or **p < 0.01 vs. vehicle; ##p < 0.01 vs. vehicle + CSDS). G, H Quantitative analysis showing the influence of 1, 5, or 10 days of interval between the single MPL injection (400 μg/kg) and stress exposure on the time spent in the center region of the open field (G) and the total distance (H) in the OFT in mice treated with or without CSDS and/or MPL (n = 10, **p < 0.01 vs. vehicle; ##p < 0.01 vs. vehicle + CSDS). Data are shown as mean ± SEM. For the results in model 1 and 2 in B, C, E, G, comparisons were made by two-way ANOVA followed by Bonferroni test, and for the results in model 3 in B, C, E, G, comparisons were first made by two-way ANOVA, and then made a further comparison between MPL pretreatment and stress exposure using t test according to the interaction report in ANOVA. For D, F, H, comparisons were only made by two-way ANOVA