慢性间歇低压低氧暴露对小鼠空间记忆及海马谷氨酸受体磷酸化水平的影响

目的:观察慢性间歇低压低氧暴露对成年C57小鼠认知功能、海马区p-Glu R-831、845位点蛋白表达以及海马区突触囊泡释放的影响。方法:雄性C57小鼠,随机分为对照组(n=16)与暴露组(n=16)。暴露组给予每天6 h 5000 m低压低氧暴露,持续4w;对照组无低压低氧暴露。两组小鼠其他饲养条件一致。利用Morris水迷宫实验检测每组小鼠空间记忆能力;免疫印迹实验检测Glu R1蛋白ser831和ser845位点磷酸化水平变化;透射电镜实验观察低氧对突触囊泡的影响。结果:(1)水迷宫结果显示慢性间歇低压低氧暴露后,暴露组平均逃脱潜伏期(17.6±1.69 s)显著低于对照组(27.3±1.45 s),暴露组小鼠平台搜索能力提升;(2)免疫印迹结果显示,暴露组小鼠海马Glu R1蛋白ser831和ser845位点磷酸化水平显著高于对照组小鼠;(3)透射电镜结果显示,暴露组小鼠海马区突触囊泡数目显著多于对照组,且差异有统计学意义。结论:慢性间歇低压低氧暴露可以显著提升C57小鼠空间认知功能,其机制可能是通过增加Glu R1蛋白ser831和ser845位点磷酸化水平,并增加突触结构内囊泡数目。

Effect of Chronic Intermittent Hypobaric Hypoxia to the Spatial Memory andPhosphorylation of Glutamate Receptor in Hippocampus

Objective:To investigate the effect of chronic intermittent hypobaric hypoxia exposure on mice spatial memory function,and on the release of synaptic vesicle and the phosphorylation of protein GluR1 ser831/ser845 in hippocampus.Methods:Adultmale C57 mice, were randomly divided into control group (n = 16) and hypoxia group (n = 16). The hypoxia group were given six hoursof 5000m exposure per day, lasting for 4 weeks while the control group were feeding in normal environment. There was no difference inother feeding condition. Morris water maze was employed to test the mice spatial memory ability. Western blot was used to test the phosphorylationof protein GluR1 ser831 and ser845. The transmission electron microscope was used to measure the release of synaptic vesiclein hippocampus.Results:(1) In the Morris Water Maze test, the average escape latency in the hypoxia group (17.6± 1.69 s) was decreasedcompared with that in the control group (27.3± 1.45 s), and the ability to searching platform increased significantly in the hypoxiagroup. (2) The Western blot result showed that level of phosphorylation of protein GluR1 ser831/ser845 in hippocampus in hypoxiagroup are both significantly higher than that in control group; (3) The results of transmission electron microscopy showed that the level ofsynaptic vesicle in hypoxia group is significantly higher than that in control group.Conclusion:The exposure of chronic intermittent hypobarichypoxic can significantly enhance mice spatial memory ability, increase the phosphorylation of protein GluR1 ser831/ser845 andthe release of synaptic vesicle in hippocampus of adult C57 mice.