高原低氧暴露下海马中M1AChR表达对雄性大鼠学习和记忆的影响  

Effects of M1 AChR expression in hippocampus on learning and memory of rats exposed to plateau hypoxia

作　　者：冯江鹏 黄灵泉 杨全余[2,3,4] 嘎琴 李生花[1] 靳国恩 FENG Jiangpeng;HUANG Lingquan;YANG Quanyu;Gaqin;LI Shenghua;JIN Guo'en(Department of Basic Medicine,Medical College,Qinghai University,Xining 810016,China;Research Center for High Altitude Medicine,Qinghai University,Xining 810001,China;Key Laboratory of Plateau Medicine,Ministry of Education,Xining 810001,China;Qinghai Plateau Medical Laboratory,Xining 810001,China)

机构地区：[1]青海大学医学部基础医学部,西宁810016 [2]青海大学高原医学研究中心,西宁810001 [3]教育部高原医学重点实验室,西宁810001 [4]青海省高原医学实验室,西宁810001

出　　处：《中国高原医学与生物学杂志》2024年第2期73-82,共10页Journal of Chinese High Altitude Medicine & Biology

基　　金：国家自然科学基金项目(No.81974283);国家重点研发设计项目(2022YFC2403705)。

摘　　要：目的 考察高原低氧暴露下海马中毒蕈碱型乙酰胆碱受体M1(muscarinic acetylcholine receptor M1,M1 AChR)表达对雄性大鼠学习和记忆的影响。方法 将大鼠随机分为常氧对照组(NC组)、常氧组(N组)、低氧组(H组)和低氧+TAK-071组(HT组)。采用定位巡航实验和空间探索实验分别考察大鼠的学习和空间记忆能力;采用苏木素-伊红染色(hematoxylin-eosin staining,H&E)技术观察大鼠额叶和海马的组织形态;采用免疫组织化学(immunohistochemical,IHC)染色和蛋白质印迹(Western Blot,WB)技术测定大鼠海马组织中M1 AchR的蛋白表达水平;采用荧光定量PCR(quantitative PCR,qPCR)技术测定大鼠海马组织中M1 AchR和叉头框蛋白P2(forkhead box protein P2,FOXP2)的基因表达水平。结果 经过Morris水迷宫(morris water maze,MWM)训练后,大鼠海马组织中M1 AChR的蛋白总体表达水平明显降低(P<0.05),但在海马CA1区、CA3区显著增加(P<0.05)。低氧环境会明显改变大鼠在定位巡航实验中的表现:逃避潜伏期时长增加;明显改变大鼠在空间探索实验中的表现:在目标象限的停留时间减少(P<0.05)。激活M1AChR后,大鼠海马组织中因低氧增加的M1 AChR明显降低(P<0.05)。结论 激活M1 AChR可以改善高原低氧对雄性大鼠的记忆损伤,减缓记忆衰退进程;对学习改善无影响。推测M1 AChR在雄性大鼠认知功能中的作用可能是保持已有记忆。Objective To investigate the effects of the expression of muscarinic acetylcholine receptor M1(M1 AChR)in hippocampus on learning and memory of male rats exposed to plateau hypoxia.Methods The rats were randomly divided into normoxic control group(NC group),normoxic group(N group),hypoxia group(H group)and hypoxia+TAK-071 group(HT group).Their learning and spatial memory abilities were investigated by place navigation test and spatial probe test respectively.Hematoxylin-eosin staining(H&E)technique was used to observe the morphology of frontal lobe and hippocampus of rats.Immunohistochemical staining(IHC)and western blot(WB)were adopted to detect the protein expression level of M1 AchR in rat hippocampus.Fluorescence quantitative PCR(qPCR)was used to detect the gene expression levels of M1 AchR and forkhead box protein P2(FOXP2)in rat hippocampus.Results After morris water maze(MWM)training,the overall expression level of M1AChR protein in rat hippocampus decreased significantly(P<0.05),while increased significantly in hippocampus CA1 and CA3 areas(P<0.05).Hypoxia environment significantly altered the performance of rats in place navigation test,i.e.an increase in escape latency duration.Besides,it significantly altered the performance of rats in spatial probe test,i.e.reduced residence time in the target quadrant(P<0.05).After activating M1 AChR,M1 AChR increased due to hypoxia in rat hippocampus decreased significantly(P<0.05).Conclusion Activating M1 AChR can improve the memory impairment of male rats caused by plateau hypoxia and slow down the process of memory decline.It has no effect on learning improvement.It is speculated that the role of M1 AChR in the cognitive function of male rats may be the preservation of existing memories.

关 键 词：高原 低氧 学习 记忆 海马 毒蕈碱型乙酰胆碱受体M1 

分 类 号：Q427[生物学—神经生物学]