Effect of sevoflurane on memory retrieval in mice : the role of hippocampal PSD95 and AMPA receptor / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of sevoflurane on memory retrieval in mice and the role of hippocampal PSD95 and amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) receptor.Methods Sixty-four healthy pathogen-free Kuming mice of both sexes,aged 2-3 months,weighing 30-35 g,were divided into control group (n =32) and sevoflurane group (n =32) in a stratified randomized block design.The ability of memory retrieval was evaluated using dark avoidance test.After setting up the memory of dark avoidance,the mice inhaled 40％ oxygen for 2 h in control group and 3.3％ sevofluane in 40％ oxygen for 2 h in sevoflurane group.Dark avoidance test was performed at 12,24,48 and 72 h after the end of oxygen or sevoflurane inhalation (T1-4),and the test results and development of amnesia were recorded.The animals were sacrificed after behavior test at each time point,and brains were removed and cut into sections which were stained with haematoxylin and eosin for examination of the pathological changes of hippocampal CA1 area (under a light microscope) and for determination of the expression of PSD95 and AMPA receptors in hippocampi (using immunohistochemistry and Western blot).Results Compared with control group,the step-in latency and test results of error times were significantly decreased,the expression of PSD95 and AMPA receptors in hippocampus was down-regulated,and the incidence of amnesia was increased at T1 and T2 in sevoflurane group (P＜0.05).Compared with the basic results,no significant change was found in the step-in latency or test results of error times in control group (P＞0.05),and the step-in latency and test results of error times were significantly decreased at T1 and T2 in sevoflurane group (P＜0.05).Apoptosis in pyramidal cells was not found in sevoflurane group.Conclusion Sevoflurane can inhibit the ability of memory retrieval transiently in mice,and the mechanism is related to inhibiting the expression of hippocampal PSD95 and AMPA receptors.