| Objective:To observed the effect of sevoflurane on the latency and error times of the passive avoidance test and the changes in the expression of PSD95 and AMP A receptors in the hippocampus.In order to evaluate the effect of sevoflurane on short-term memory retrieval in adult mice and to explore its possible mechanism.Methods:144 Kunming mices,healthy and clean,2～3 months old,female and male,weighed 30-35 g.Mices were randomly divided into two groups:A(n=64)and B(n=80),according to the random number table.They participated in the step-through test and the step-down test respectively.The group A was divided into 2 groups(n=32)according to the random:the control group(inhaled 40%O2 2h),sevoflurane group(3.3%sevoflurane and 40%O2 2h).The group B was randomly divided into 2 groups(n=40):the control group(inhaled 40%O2 2h),sevoflurane group(3.3%sevoflurane and 40%O2 2h).According to the test points of behavioral indicators,8 mices were randomly selected from two groups of mices in the A respectively,at point 12h(Ti),24h(T2),48h(T3)and 72h(T4)after stop inhaling sevoflurane or oxygen.Then measured the step-through lantency and error times in 5 minutes,each mouse was only tested once.In the B group,10 mices were randomly selected at point 12h(Ti),24h(T2),48h(T3)and 72h(T4)respectively after stop inhaling sevoflurane or oxygen,then measured the step-down lantency and error times in 5 minutes.In order to evaluate the ability of short-term memory retrieval and the occurrence of forgetting.After the behavioral test,mices were killed and the tissues of hippocampus were taken for HE staining.The pathological findings in hippocampus were observed under optical microscope.The expression level of PSD95 protein and AMP A receptors in hippocampus were detected by immunohistochemistry and Western blot.Results:(1)Behavioral test results:group A:compared with the control group,the step-through latency of Ti and T2 in sevoflurane group were shortened,and the error times were increased in 5 minutes,the differences were significant.Compared with the basic scores,there were no differences significantly with step through lantency and the error times in the control group(P>0.05).But the step-through lantency scores of sevoflurane group were significantly shorter than basic scores at Ti and T2,and the error times scores were significantly higher than basic scores(P<0.05).Group B:compared with the control group,the step-down lantency had shortened and the error times had risen in sevoflurane group at Ti.Compared with the basic scores,there were no differences significantly with step-down lantency and the error times in the control group(P>0.05).But the step-down lantency scores of sevoflurane group were significantly shorter than basic scores at Ti,and the error times scores were significantly higher than basic scores(P<0.05).(2)Protein results:Compared with the control group,the expression level of PSD95 and AMPA receptors in the hippocampus were decreased at T1 and T2 in the sevoflurane group,the differences were significant(P<0.05).(3)Result of the HE staining:The nerce-cells partial to swelling,but there were no apoptosis of pyramidal cells were found in the sevoflurane group obviously.Conclusion:Sevoflurane can inhibit the short-term memory retrieval in adult mice.May be related to the inhibition of the expression of PSD95 and AMPA receptors in the hippocampus,which leads to effective synaptic transmission were decreased. |
