| Objective: Nowadays,the pace of life increases and the pressure of work increases,causing many people to suffer from sleep disorders.Especially for the elderly patients admitted to the hospital,due to anxiety state,environmental changes after admission,and the pain caused by the disease,there is a long sleep disorder in the hospital.It’s even more important for patients who need surgery.Postoperative cognitive dysfunction is closely related to the state of preoperative patients,but its and the inner link between sleep disorder is not clear,and how to effectively improve the postoperative cognitive dysfunction which is caused by sleep disorder still needs further investigation.The purpose of this study is to observe the cognitive function changes after laparotomy in rats with sleep deprivation and compare the expression of inflammatory mediators in the hippocampus of rats,to explore the mechanism of postoperative cognitive changes in rats after sleep deprivation and the role and possible mechanism of dexmedetomidine in the postoperative cognition of rats after sleep deprivation.Method: In this study,SD rats were used to complete the preparation of the 48 h sleep deprivation model with the help of self-made platform water environment method.Study rats were divided into six groups: Sham group,Surgery group,SD+S group,DEX+SD+S group,MDSS group,MLA+SD+S group.The rats in SD+S group,DEX+SD+S group,MDSS group,MLA+SD+S group were prepared by using self-made platform water environment method to establish the 48 h sleep deprivation model.The rats in DEX+SD+S group,MDSS group were injected dexmedetomidine with a dose of 5ug/kg in the onset of sleep deprivation and sleep deprivation 24 hours.The rats in the MDSS group were injected MLA in the intraperitoneal cavity with a dose of 40ug/kg for the first 15 min of dexmetomidine.The changes of cognitive ability in rats were observed using Morris water maze experiment.Using Western Blot technique,the changes in the content of inflammatory cytokines(IL-1,IL-6,TNF-α,NF-κB)in the hippocampus of rats were observed.Results: Surgery intervention can reduce the spatial memory ability of rats,and significantly decrease the percentage of distance and time spent in the platform quadrant (P<0.05),but there was no statistical difference in the number of crossing platforms.The rats with sleep deprivation significantly reduced postoperative spatial memory ability.In exploring experiment of the Morris water maze,the percentage of time and distance spent in the platform quadrant of this group significantly decreased compared with that of the operation group,with statistical difference(P<0.05).Dexmedetomidine has a protective effect on the spatial memory of rats with sleep deprivation.Compared with the SD group,this group showed statistically significant difference in the percentage of time and distance of the platform in the exploration experiment(P<0.05).The protective effect of dexmedetomidine can be reversed by α7n Ach R blocker MLA.Compared with the DEX+SD+S group,the time percentage and distance percentage of the platform in the MDSS group significantly decreased,with statistical difference(P<0.05).Surgical intervention can make hippocampal inflammation reaction activation.Compared with sham group rats,the content of inflammatory cytokines(IL-1,IL-6,TNF-α,NF-κB)significantly increased,with statistically significant difference(P<0.05).The content of inflammatory cytokines(IL-1,IL-6,TNF-α,NF-κB)were significantly higher in the hippocampal area of rats after sleep deprivation.Dexmedetomidine can effectively inhibit the inflammatory response in the hippocampus of rats with sleep deprivation.In this group,the pro-inflammatory cytokines(IL-1,IL-6,TNF-α,NF-κB)were significantly reduced in the hippocampus of the rats(P<0.05).The anti-inflammation effect of dexmedetomidine can be reversed by α7n Ach R blocker MLA.Compared with DEX+SD+S group,the inflammatory cytokines(IL-1,IL-6,TNF-α,NF-κB)in the hippocampus were significantly higher than those in the MDSS group,with statistically significant differences(P<0.05).Conclusion: Postoperative cognitive decline is associated with activation of inflammatory responses in the hippocampus.Preoperative sleep deprivation amplifies the inflammatory response in the hippocampus,leading to significant cognitive decline.Dexmedetomidine can effectively reduce the inflammation in the hippocampus after sleep deprivation and improve the postoperative cognitive function of sleep deprivation rats,and its protective effect is related to α7n AchR. |
