The Mechanisms Underlying The Involvement Of Glucocorticoid Receptor In The Electroacupuncture Regulating The Posttraumatic Stress Disorder

Objective: To observe the effects of Electroacupuncture on the fear memory caused by post-traumatic stress disorder and explore the mechanisms underlying the involvement of GR in the Electroacupuncture regulating the Posttraumatic Stress Disorder.Methods: Single prolonged stress model was used as the animal model for this experiment study.In experiment 1(SPS 10d),mice were randomly divided into normal group(N),model group(M).Fear conditioning,Tail suspension,Forced swim test were used to make sure the SPS model is working.In the experiment 2(SPS 20d),mice were randomly divided into normal group(N),model group(M),sham electroacupuncture group(S),electroacupuncture group(EA).EA group choose acupoints Zusanli and Baihui for electroacupuncture intervention for 5 times after modeling 7 days.Fear conditioning,Tail suspension,Forced swim and Elevated zero maze behavioral tests were used to detect fear memory and anxiety-like behavior among all group after electroacupuncture treating.The concentrations of Corticosterone(CORT)and Adrenocor Ticotropic Hormore(ACTH)in peripheral blood of each group of mice were checked by Radioimmunoassay.The brain tissues of each group were subjected to immunofluorescence staining of GR,Neu N,p-CREB and DAPI.Detected the GR expression of nuclear protein in prefrontal cortex,hippocampus and amygdala,checked the Brain derived neurotrophic factor(BDNF),p-CREB,p-Erk,FKBP5 and SKA2 expression of total protein in prefrontal cortex and hippocampus,Corticotropin Releasing Factor(CRF),Corticotropinreleasing Factor receptor 1(CRFR1)expression in the hypothalamus by Western Blot.Used ELISA to detect the amygdala BDNF and 5-Hydroxytryptamine(5-HT)levels.In the experiment 3,mice were randomly divided mice into normal group(N+V),model group(SPS+V),RU intervention group(SPS+RU),electroacupuncture group(SPS+EA).In the RU group,the GR antagonist RU 38486 was intraperitoneally injected 5 min before modeling,and observed the behavior changes among all group mice after electroacupuncture treating.Result: 1.Experiment 1: Behavioral tests found that compared with N group mice,the percentage of freezing time in M group was significantly increased(P<0.05);In Tail suspension and Forced swim experiment,compared with the N group,the immobility time of the M group was significantly increased,and compared with the M group,the immobility time of the EA group was significantly reduced(P<0.05).2.Experiment 2: Behavioral tests showed that compared with N group,the percentage of freezing time in M group was significantly increased(P<0.05),and compared with M group mice,EA group was significantly decreased(P<0.05).compared with M group,the immobility time of mice in EA group was significantly decreased in Tail suspension and Forced swim experiment(P<0.05),In Elevated zero-maze test,compared with N group,the time in open arm of M group and S group was decreased(P<0.05),while compared with M group,EA group was much higher(P<0.05).Compared with N group,the ACTH and CORT levels in the M group were significantly decreased(P<0.05).Compared with M group,the ACTH concentration in the EA group was much higher(P<0.05).Compared with the N group,the hypothalamic CRF expression in the M group was increased,compared with the M group,S group was decreased(P<0.05).The results of immunofluorescence and Western Blot all showed that compared with the N group,the Nuclear protein of GR expression in M group was significantly increased(P<0.05)in the prefrontal cortex,hippocampus and amygdala,compared with the M group,EA group Nuclear protein of GR expression in hippocampus was significantly decreased(P<0.05).Compared with N group,the expression of p-CREB,BDNF in M group was significantly decreased in the hippocampus protein(P<0.05).Compared with N group,the expression of SKA2 in M group and S group were increased(P<0.05)in hippocampus.Compared with N group,amygdala CRF and CRFR1 expression in M group were significantly higher(P<0.05),compared with M group,amygdala CRF expression of EA group was decreased(P<0.05).The 5-HT level in M group was decreased compared with N group mice in the amygdala.3.Experiment 3: Behavioral tests suggested that,compared with SPS+V group,SPS+RU group and SPS+V+EA group was significantly decreased(P<0.05);compared with N+V group,the time enter to the open arms of SPS+V group mice in the elevated zero maze was significantly decreased(P<0.05).In Tail suspension experiment,compared with SPS+V group,the SPS+V+EA group were decreased(P<0.05).In Forced swimming experiment,compared with N+V group,SPS+V group immobility time was significantly increased(P<0.01),SPS+RU group and SPS+V+EA group were elevated too.(P <0.05).Conclusion:Electroacupuncture can improve the behavioral changes of fear memory regression disorder in SPS model mice by alleivating HPA axis dysfunction and regulating GR expression in the central nervous system.The mechanisms underlying electroacupuncture alleviate the anxiety-like behavior of SPS model mice involving the amygdala CRF expression.