Correlation Between Decreased Number Of Astrocytes And Postoperative Cognitive Dysfunction In Aged Rats

Background:Cognitive dysfunction after surgery can lead to learning and memory ability of patients after surgery,loss of personality and social behavior,including verbal memory,visual memory,language comprehension and visual space cognitive domain dysfunction,drastically impact the health of the patients quality of life,extend the rehabilitation period and increase the cost of hospitalization,and delay organ function recovery,and even increase the mortality of patients.Has completely to the aging society in our country,and the elderly is POCD high-risk groups,high incidence of POCD and great harm to the whole China’s social and family brought great economic and mental burden,the society as a whole for the elderly health costs will increase,aging population average medical expenses growth speed significantly faster than the average growth rate of GDP,the limited medical resources and economic resources have been unable to meet the new family the rising cost of health insurance medical service.Therefore,the country,society and people are in urgent need of reducing POCD occurrence.During general anesthesia,the use of anesthetic drugs,the stimulation of surgical operation,the occurrence of inflammatory reaction and the change of cerebral hemodynamics may cause direct damage to brain neurons,and at the same time,the functional state of brain astrocytes will also be affected.Changes in the number or structure of brain astrocytes may lead to or aggravate the occurrence of POCD.Therefore,this study aims to study the occurrence mechanism of POCD from the perspective of changes in the number of brain astrocytes.Objective: To investigate the incidence of POCD increased in elderly rats after general anesthesia operation.The number of astrocytes in hippocampus and the expression of GFAP in serum were evaluated.To study the correlation between decreased astrocytes and postoperative cognitive dysfunction in aged rats.Methods: Thirty SD rats aged 16 months were prepared,10 of which were used as control group,10 of which inhaled sevoflurane anesthesia,and the rest 10 were established as postoperative cognitive dysfunction model.Morris water maze test was implemented in all rats before the experiment to measure 5-day escape latency before the operation.After the operation,the escape latency on 1st,3rd and 5th day was also measured respectively through Morris water maze.After that blood was taken and brains severed and collected from all rats.Immunohistochemical staining was used to detect the number of astrocytes in hippocampus and cerebral cortex,and ELISA was applied to determine the serum GFAP concentrationResults:(1)The Morris water maze experiment was performed on elderly rats and compared the results obtained in the anesthesia group and the anesthesia surgery group.It was shown that both can cause cognitive dysfunction in the experimental animals,and the conditions caused by the two groups were compared.The results showed that the surgery group was more serious,and the cognitive function of the experimental animals in this group was significantly decreased,which was significantly different from the other group,and the cognitive dysfunction of the elderly rats in the anesthesia operation group was more severe,with statistically significant difference(P<0.05).(2)Immunohistochemical staining analysis showed that astrocytes were significantly reduced in both anesthesia group and anesthesia operation group,and significantly decreased in anesthesia operation group.(3)The study was conducted in the anesthesia group and the anesthesia surgery group,using the ELISA method,the results showed that the serum GFAP concentration of the two groups of animals changed,showing a significant increase,and there were differences between the two groups,of which the anesthesia surgery group changed It is more obvious,and the relative improvement is higher(P<0.05).(4)Pearson’s correlation analysis showed that the number of astrocytes in the hippocampal CA1 region was negatively correlated with the escape latency 1 day after surgery(r=-0.821,P<0.05;r = 0.969);The serum GFAP concentration was positively correlated with the escape latency 1 day after operation(r=0.939;r = 0.933,r = 0.861,P<0.05).Conclusion: Sevoflurane general anesthesia and abdominal exploration can cause cognitive dysfunction in aged rats,and the cognitive dysfunction in aged rats is related to the decrease in the number of astrocytes.