Mechanism Of Pathological Changes In Amygdala Of Male Offspring Induced By Chronic Stress During Pregnancy

Objective To explore the mechanism of depression and pathological changes in amygdala of male offspring induced by chronic stress during pregnancy.Experiment 1Methods:Twenty female KM pregnant mice were randomly divided into normal control group and chronic stress group.After brith,male offspring mice were divided into the control group(CON),the control + saline group(CON + SAL),the chronic pregnancy stress group(CPS),the chronic pregnancy stress + saline group(CPS + SAL)and the chronic pregnancy stress + NMDAR antagonist group(CPS + ANT1).There were 10 mice in each group and 50 mice in total.NMDAR antagonist(MK-801)was injected intraperitoneally in CPS + ANT1 group within 10-30 days after birth,and saline was injected intraperitoneally in CPS + SAL group and CON + SAL group within 10-30 days after birth.On the 31 st day,the depression degree of the offspring was detected by behavioral experiment;The concentration of CRH in the blood was detected by ELISA kit;Western blot was used to detect the protein contents of mTOR and p-mTOR(ser2448)in amygdala;The pathological changes of amygdala were observed by HE staining;The apoptosis of amygdala neurons was detected by TUNEL staining;The complexity of amygdala neurons and the density of dendritic spines were detected by Golgi Cox staining.Results : Behavioral test results showed that the swimming immobility time and sugar water preference rate of KM mice in the CPS + SAL group were significantly changed compared with those in the CON + SAL group(P < 0.05),and the swimming immobility time and sugar water preference rate of the CPS + ANT1 group were significantly improved compared with those of the CPS + SAL group(P < 0.05).HE,TUNEL and Golgi Cox staining showed that the number of neurons and the degree of neuronal apoptosis in the amygdala were significantly increased(P < 0.05)and the complexity of neurons and the density of dendritic spines were significantly decreased(P < 0.05)in the CPS + SAL group compared with the CON + SAL group.However,compared with the CPS + SAL group,the CPS + ANT1 group showed a significant decrease in the number of neurons in the amygdala,the extent of neuronal apoptosis(P < 0.05),a significant increase in neuronal complexity and dendritic spine density(P < 0.05),and an improvement in the pathological damage of the amygdala.WB assay and ELISA results: compared with the CON + SAL group,the CPS + SAL group showed significantly higher CRH content in blood(P < 0.05),lower mTOR and p-mTOR expression in amygdala tissue(P < 0.05),and higher CRH content in blood(P < 0.05),and higher mTOR and p-mTOR expression in amygdala tissue(P < 0.05)than the CPS + SAL group.Experiment 2:Methods:Twenty female KM pregnant mice were randomly divided into normal treatment group and chronic stress group.After brith,male offspring mice were divided into the control group(CON),the control + solvent group(CON + SOL),the chronic pregnancy stress group(CPS),the chronic pregnancy stress + solvent group(CPS + SOL)and the chronic pregnancy stress + CRHR1 antagonist group(CPS + ANT2).There were 10 mice in each group and 50 mice in total.There were 10 mice in each group and 50 mice in total.CRHR1 antagonist(Antarlamin)was injected intraperitoneally in CPS + ANT2 group 10-30 days after birth,and solvent(containing 2% Tween-80 saline)was injected intraperitoneally in CPS + SOL group and CON + SOL group 10-30 days after birth.On the 31 st day,the depression degree of the offspring was detected by behavioral experiment;The concentration of CRH in the blood was detected by ELISA kit;Western blot was used the protein contents of mTOR and p-mTOR(ser2448)in amygdala were detected;The pathological changes of amygdala were observed by HE staining;The apoptosis of amygdala neurons was detected by TUNEL staining;The complexity of amygdala neurons and the density of dendritic spines were detected by Golgi Cox staining.Results : Behavioral test results showed that the swimming immobility time and sugar water preference rate of KM mice in the CPS + SOL group were significantly changed compared with those in the CON + SOL group(P < 0.05),and the swimming immobility time and sugar water preference rate of the CPS + ANT2 group were significantly improved compared with those of the CPS + SOL group(P < 0.05).HE,TUNEL and Golgi Cox staining showed that the number of neurons and the degree of neuronal apoptosis in the amygdala were significantly increased(P < 0.05)and the complexity of neurons and the density of dendritic spines were significantly decreased(P < 0.05)in the CPS + SOL group compared with the CON + SOL group.However,compared with the CPS + SOL group,the CPS + ANT2 group showed a significant decrease in the number of neurons in the amygdala,the extent of neuronal apoptosis(P < 0.05),a significant increase in neuronal complexity and dendritic spine density(P < 0.05),and an improvement in the pathological damage of the amygdala.WB assay and ELISA results: compared with the CON + SOL group,the CPS + SOL group showed significantly higher CRH content in blood(P < 0.05),lower mTOR and p-mTOR expression in amygdala tissue(P < 0.05),and higher CRH content in blood(P < 0.05),and higher mTOR and p-mTOR expression in amygdala tissue(P < 0.05)than the CPS + SOL group.Conclusion: CRH may mediate the impact of CPS on depression in male offspring.It is through activating NMDAR and CRHR1 and decreasing mTOR protein expression in amygdala,which resulted in the neuron injury and pathological damage of amygdala in male offspring.