The Influence Of Repeated Sevoflurane Exposure On The Learning And Memory Function In Aged Rats

BlackgroundPOCD is one of the most common postoperative complications, specially old patients, which seriously affect quality of life and increase mortality in postoperative patients. Age is one of the main factors that cause the occurrence of POCD, but the mechanism of POCD is still not clear.ObjectiveThe present study is to expore the effect of the repeated sevoflurane exposure on learning and memory of aged rats and the role of beta-amyloid protein(A?) and phosphorylated-tau protein(p-tau) in its mechanism.MethodTwenty male Sprague-Dawley rats were randomly divided into 2 groups(n=10in each), group S(sevoflrane) and group C(control). The rats of group S was exposure to 2.1% sevoflurane 2h after induced by 5% sevoflurane every week when it is 20 month old. Oxygen only to control group. The function of learning and memory was tested by Morris water maze experiment. And the expression of A? and p-tauin hippocampus tissue was detected by immunohistochemistry.ResultsCompared with control group, the escape latency and the platform-crossing frequencies of sevoflurane group had no significant difference(P > 0.05). However,the target quadrant traveling time had(P < 0.05).There was no significant difference between S group and C group on the expression of A? and p-tau inthe CA1 area of hippocampus(P > 0.05).ConclusionsAt this experiment, repeated sevoflurane exposure in 2.1% could slow the function of learning and memory decline, especially memory function, in aged rats.There was no significant effect on the expression of A beta and p-tau protein in hippocampal CA1 region.