Objective To establish a postpartum depression animal model induced by pre-pregnancy stress,assess abnormal maternal depressive-like behavior,observe the expression of disrupted-in-schizophrenia 1 (DISC1) in the hippocampus,and detect serum estradiol and corticosterone.Methods A total of 32 female Balb/c were assigned to two groups using random number table:the control group and the pre-pregnancy stressed group(model group),and the model group was subjected to 3 weeks of chronic restraint stress. After the last stressor,the control group and the model group were housed with a male. About 4 weeks later,the mice gave birth to pups. Then at 3 weeks postpartum,open field test,tail suspension test,and sucrose preference test were carried out. The expressions of DISC1 mRNA and protein of hippocampus were detected by real-time quantitative polymerase chain reaction and Western blot,respectively. The serum levels of estradiol and corticosterone were detected with enzyme linked immunosorbent assay. Results After 3 weeks of postpartum,the model mice showed depression-like behaviors. In the open field test,there was no effect on the total distance moved or time spent in the center field (P>0.05). Immobility in tail suspension test was significantly increased (t=-4.950,P<0.001) and sucrose preference was significantly reduced in model group (t=2.475,P<0.05). There was significant statistical difference between control and model group on the expression of DISC1 mRNA (t=-8.915,P<0.001) and protein (t=-5.004,P<0.01) in hippocampus. There was no significant statistical difference on estradiol and corticosterone between two groups (P>0.05). Conclusion Chronic pre-pregnancy stress can induce dams into postpartum depression.The pathogenesis of postpartum depression may be related to the regulation of DISC1 in the hippocampus.

Aim Using chronic pre-pregnancy stress to establish a postpartum depression animal model, given a single YG,and acute ketamine was served as control, to explore the pathology of PPD and the anti-depressive mechanism of the YG on the PPD model on AKT/mTOR signaling pathway. Methods Thirty-two fe-male Balb / c were randomly assigned to two groups, the control group ( Control, Con) and the pre-pregnancy stressed group(Model,Mod) , which was subjected to 3 weeks chronic restraint stress. After the last stressor, the pre-pregnancy stressed group was housed with a male. After about 4 weeks later, the mice gave birth to pups. Then at 3 weeks postpartum, we tested the ma-ternal tail suspension test ( TST). Both YG and Ket-amine was single administered 24 hours before behavior test, with single saline for control group and PPD mod-el group. After TST,the mouse hippocampus were ex-tracted to detect the expression of AKT and mTOR. Results After 3 weeks postpartum, the model mice showed depression-like behaviors. Immobility in TST was significantly increased in vehicle groups(P <0. 01). Acute YG improved performance in the TST (P< 0. 01), which was similar to ketamine. And the PPD model mice group showed decreased phosphorylation of AKT and mTOR (P < 0. 01,P < 0. 01), compared to control group. A single dose of YG or ketamine normal-ized AKT/ mTOR signaling in the PPD model mice(P< 0. 01,P < 0. 01),( P < 0. 01,P < 0. 01). Conclu-sions Chronic pre-pregnancy stress can induce dams into postpartum depression and its mechanism maybe associated with down-regulating AKT/ mTOR signa-ling. Acute YG exerts fast antidepressant effect on this PPD model similar to ketamine, and its mechanism may be related to up-regulating AKT/ mTOR signaling in the hippocampus.

Aim To establish a postpartum depression animal model,assess the abnormal maternal behaviors of depressive dams,and observe the rapid antidepres-sant effects of the Yuejuganmaidazaotang (YG)on the PPD model.Methods Thirty-two female Balb /c were randomly assigned to two groups,the control group (Control,con)and the pre-pregnancy stressed group (Vehicle,veh),and vehicle was subjected to 3 weeks chronic restraint stress.After the last stressor,the pre-pregnancy stressed group was housed with a male.Af-ter about 4 weeks later,the mice gave birth to pups. Then at 3 weeks postpartum,we tested the maternal depressive-like behaviors,including sucrose preference test,forced swimming test and novelty suppressed feeding test.Both YG and Ketamine were single ad-ministered 24 hours before behavior test,with single saline for control group and PPD model group.Results After 3 weeks postpartum,the vehicle mice showed depression-like behaviors.Reduced preference in drinking sucrose solution was found in SPT (P <0.01 ).Immobility in FST was significantly increased in vehicle groups (P <0.01 ).In NSFT,the vehicle group displayed a significantly increased latency and reduced unit of food intake compared with control group(P <0.01,P <0.01 ).Acute YG improved per-formance in the SPT(P <0.01),FST (P <0.01)and NSF (P <0.01,P <0.01),which was similar to ket-amine.Conclusions Chronic pre-pregnancy stress can induce dams into postpartum depression.Acute YG exert fast antidepressant effect on this PPD model simi-lar to ketamine.