Study On The Effects Of BDNF And Protective Mechanisms Of R-ketamine In Post-stroke Depression Rats

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Establish the PSD rats model and investigate the effects of different forms of BDNFObjective:To investigate the functions of different forms of brain-derived neurotrophic factors(BDNF),including BDNF precursor(BDNF),mature BDNF and BDNF pro-peptide,in the post-stroke depression(PSD)rats model.Methods:Compound PSD rats model was established by combining chronic unpredictable mild stress(CUMS)with the model of focal cerebral ischemia built by using the middle cerebral artery occlusion(MCAO).Divide into 4 groups,each group were 15 rats,including the control group,stroke group,depression group and model group.Select the brain tissues that are closely related to depression after one week,including the prefrontal cortex(PFC),nucleus accumbens(NAc),dentate gyrus(DG)and CA3 in the hippocampus.Use real-time polymerase chain reaction(RT-PCR)and Western blot to detect the mRNA and protein expression levels of different forms of BDNF(including proBDNF,BDNF pro-peptide and mature BDNF).Results:The mRNA and protein levels of proBDNF and BDNF pro-peptide of PSD group were significantly higher than those of the control group(P<0.05),while the mRNA and protein levels of mature group were significantly lower than that of the control group(P<0.05),in PFC,DG and CA3 of hippocampus.The mRNA and protein levels of proBDNF and BDNF pro-peptide of PSD group were significantly lower than those of the control group(P<0.05),while the mRNA and protein levels of mature group were significantly higher than that of the control group(P<0.05),in NAc region.Conclusion:The PFC,NAc,DG and CA3 of the hippocampus are closely related to the development of PSD in rats model.ProBDNF,BDNF pro-peptide and mature BDNF all play an important role in the above brain regions,nevertheless,proBDNF and BDNF pro-peptide have an opposite effect to mature BDNF.Part ? Study on the protective effect of R-ketamine in rats PSD modelObjective:To investigate the protective effect of R-ketamine in rats PSD model,and compare the antidepressant effect of fluoxetine,R-ketamine and S-ketamine.Methods:Establish the rats PSD model.Divide into 5 groups,each group were 10 rats,including the control group,model group,fluoxetine group,S-ketamine group and R-ketamine group.Fluoxetine group was injected with fluoxetine 10 mg/kg intraperitoneally.S-ketamine group was injected with S-ketamine 10 mg/kg intraperitoneally.R-ketamine group was injected with R-ketamine 10 mg/kg intraperitoneally.locomotion test(LMT)was performed after injection 2h,forced swimming test(FST)was performed after injection 48 h,1%sucrose preference test(SPT)was performed after injection day 2 and day 4.Select the brain tissues that are closely related to depression as described in the first part after injection day 6.The expression levels of BDNF,glutamate receptors(GluAl),phosphorylated tyrosine kinase receptor B(p-TrkB),postsynaptic dense protein 95(PSD95)were detected by Western blot.In addition,we compared the side effects of two drugs R-ketamine and S-ketamine.Re-establish the rats PSD model.Divide into 4 groups,each group were 10 rats,including the control group,model group,S-ketamine group and R-ketamine group.S-ketamine group was injected with S-ketamine 10 mg/kg intraperitoneally.R-ketamine group was injected with R-ketamine 10 mg/kg intraperitoneally.The brain tissuessame as above were selected and the number of positive cells of Parvalbumin(PV)was observed by immunohistochemistry(IHC).Results:There was no significant difference in LMT(P>0.05);while the immobility time in R-ketamine,fluoxetine and S-ketamine group was significantly shorter than that in PSD group in FST(P<0.05);the preference in R-ketamine group was significantly higher than that in S-ketamine group,while there was no significant difference among fluoxetine,S-ketamine and PSD group(P>0.05)in twice SPT.The levels of depression-related proteins(BDNF,GluAl,p-TrkB and PSD95)in R-ketamine group were significantly higher than those in S-ketamine group(P<0.05),while there was no significant difference among fluoxetine,S-ketamine and PSD group,in PFC,DG and CA3 of hippocampus;there was no significant difference in NAc among fluoxetine,R-ketamine,S-ketamine and PSD group(P>0.05).The number of PV positive cells in S-ketamine group significantly decreased compared with those in R-ketamine group(P<0.05)in PFC and DG of hippocampus,while there was no significant difference in the number of PV positive cells among all groups(P>0.05)in NAc.Conclusion:In the antidepressant treatment of PSD rats model,fluoxetine,S-ketamine and R-ketamine all have antidepressant effects.compared with fluoxetine and S-ketamine,R-ketamine produces better efficacy,longer duration and lighter side effect.The mechanism to the long antidepressant effect is upregulating the BDNF-TrkB signaling pathway,and promoting glutamate neurotransmitter release in PFC,DG and CA3 of the hippocampus.For PSD patients,R-ketamine can be used as an effective therapeutic agent.Part ? Study on the antidepressant mechanism of R-ketamine in rats PSD modelObjective:To investigate the antidepressant mechanism of R-ketamine in rats PSD model,and compare the antidepressant effect of R-ketamine and S-ketamine.Methods:Establish the rats PSD model.Divide into 4 groups,each group were 15 rats,including the control group,model group,S-ketamine group and R-ketamine group.S-ketamine group was injected with S-ketamine 10 mg/kg intraperitoneally.R-ketamine group was injected with R-ketamine 10 mg/kg intraperitoneally.Select the brain tissues that are closely related to depression as described in the first part after one week.The changes of neuronal morphology and dendritic spine density were detected by Golgi staining.The rat PSD model was established.The rats were divided into four groups:control group,model group,S-ketamine group and R-ketamine group.S-ketamine group was injected with S-ketamine 10 mg/kg,R-ketamine group was intraperitoneally injected with R-ketamine 10 mg/kg.The changes of neuronal morphology and dendritic spine density in different brain regions were detected by Golgi staining technique.The changes of neuronal morphology and dendritic spine density in different brain regions were detected by Golgi staining technique.Re-establish the rats PSD model.Divide into 2 groups,each group were 10 rats,including S-ketamine group and R-ketamine group.S-ketamine group was injected with S-ketamine 10 mg/kg intraperitoneally.R-ketamine group was injected with R-ketamine 10 mg/kg intraperitoneally.The changes of glutamate neurotransmitter were detected by stereotactic and brain microdialysis in PFC and the hippocampus.Results:The dendritic spine density in S-ketamine and R-ketamine groups significantly increased compared with that in PSD group(P<0.05),and the dendritic spine density in R-ketamine group was significantly higher than that in S-ketamine group,in PFC and DG of hippocampus;there was no significant difference in dendritic spine density between S-ketamine and R-ketamine group(P>0.05),in NAc and CA3 of hippocampus.The levels of glutamate between S-ketamine and R-ketamine group were no significant difference at 2h before single injection,45,75 and 105 mins after single injection(P<0.05),while the levels of glutamate in R-ketamine group were significantly higher than those in S-ketamine group at 45,75 and 105 mins after single injection(P<0.05),in PFC and the hippocampus.Conclusion:In the antidepressant treatment of PSD rats model,both S-ketamine and R-ketamine have sustained antidepressant effects.Compared with S-ketamine,R-ketamine produces better efficacy and longer duration.The mechanism to the antidepressant effect is promoting glutamate neurotransmitter release,and enhancing synaptic formation in PFC,DG and CA3 of the hippocampus.