Stress susceptibility is an important aspect of depression. Thus, we evaluated the susceptibility of postpartum female mice to Subchronic unpredictable stress (SCUS). Both postpartum female mice and virgin female mice were divided into two groups: non-stressed and stressed groups. Mice in the stressed group were subjected to 3 days of CUS (Fig. 3a). SPT was conducted before and after stress exposure. Before stress exposure, a two-way ANOVA revealed no effect of fertility condition (F (1, 30) = 0.477, P = 0.495), stress (F (1, 30) = 0.132, P = 0.719) and fertility condition × stress interaction (F (1, 30) = 0.031, P = 0.037) on sucrose preference, showing that the basal depressive-like behaviors of virgin and postpartum female mice were similar (Fig. 3b). After stress exposure, there were significant effects of the fertility condition (F (1, 30) = 7.311, P = 0.011), stress (F (1, 30) = 9.080, P = 0.005) and fertility condition × stress interaction (F (1, 30) = 6.980, P = 0.013) on sucrose preference. Virgin mice showed no changes of preference for sucrose (P = 0.995),
