Based On BDNF-TrkB Signal Pathway And Synaptic Plasticity,the Mechanism Of Icariin Improving Fear And Memory Impairment In PTSD Rats

ObjectiveTo investigate the effect and mechanism of Icariin on fear memory in post-traumatic stress disorder(PTSD)rats.MethodsThirty male SD rats were used to construct PTSD rat model by single prolonged stress(SPS).The model rats were randomly divided into three groups: SPS group,icariin group and icariin + K252 a group(K252a is a Trk B inhibitor),with 10 rats in each group;Another 10 normal rats were taken as the control group.Icariin group and icariin+K252a group were administered by gavage 1 day after SPS,once a day,with a dose of 20 mg / kg.Control group and SPS group were given the same dose of normal saline.K252 a was injected into lateral ventricle.After 2 weeks,the fear memory impairment of rats in each group was detected by mine experiment,elevated cross maze experiment and conditional fear test;Molecular docking verified the binding activity of Icariin to BDNF;The expression of BDNF and Trk B in rat amygdala was detected by Immunohistochemistry;The relative expressions of BDNF and Trk B proteins were detected by Western blot.The expression of PSD95 and SYN in rat amygdala was detected by immunofluorescence.ResultsIcariin has good binding activity with BDNF.Compared with the control group,the times of entering the central area and the percentage of movement distance in the central area in SPS group and icariin+K252a group were significantly reduced,OE and OT were significantly reduced,the freezing time and defecation times were significantly increased,and the expressions of BDNF,Trk B,PSD95,SYN proteins were significantly reduced(P< 0.05);Compared with SPS group,icariin group rats significantly increased the times of entering the central area and the percentage of movement distance in the central area,significantly increased OE and OT,significantly reduced the time of immobilization and defecation,and significantly increased the expression of BDNF,Trk B,PSD95,SYN(P< 0.05).ConclusionIcariin can effectively alleviate the fear memory impairment induced by SPS in rats.This protective effect is related to the activation of BDNF/Trk B signal pathway and up-regulate the expression of PSD95 and SYN.