衰老与海马CA1区锥体细胞退行性变及自由基和空间记忆的关系  

Relationships of aging with the degeneration of CA1 pyramidal cells,free radical contents of hippocampus and spatial memory of rats

作　　者：何宏文[1] 周丽华[1] 袁群芳[1] 

机构地区：[1]中山大学中山医学院人体解剖学教研室,广东省广州市510080

出　　处：《中国临床康复》2003年第22期3044-3045,共2页Chinese Journal of Clinical Rehabilitation

基　　金：国家自然科学基金(30070952);广东省社会发展项目(2002C30111)~~

摘　　要：目的:研究衰老大鼠记忆行为、自由基含量和CA1区细胞超微结构的特征以及衰老所致记忆减退的神经生物学机制。方法:雄性SD大鼠40只,青年和老年组各20只。应用Morris水迷宫测量大鼠空间记忆水平,分光光度计测量海马组织蛋白质的含量;巴比妥酸还原法测定海马脂质过氧化物含量;透射电镜观察海马CA1区锥体细胞的形态;体视学分析细胞内粗面内质网和线粒体的面数密度。结果:较之青年大鼠,衰老大鼠寻找平台的潜伏期延长(38与12s,t=8.04,P<0.01);跨平台次数的百分比减少(50%与82%,t=10.17,P<0.05)。海马脂质过氧化物(146.2与178.4nmol/g,t=5.61,P<0.01)、组织总蛋白(127.9与168.8μg比较,t=8.25,P<0.01)和非水溶性蛋白(21.1与34.3μg比较,t=9.53,P<0.01)的含量增高;海马CA1区250μm锥体细胞的数量(51.9与40.7个比较,t=6.55,P<0.01)、核仁体积(5.34与4.02μm3,t=7.71,P<0.01)、粗面内质网面密度(1.47与0.94μm2/μm3,t=6.55,P<0.01)减少。结论:海马CA1区锥体细胞的退行性变化是衰老致记忆减退的原因之一,而过量的脂质过氧化物可能是导致锥体细胞变性的原因。AIM:To o bserve the characteristics of me mory behavior,free radical con-tents and ultr astructural morphome try of pyramidal cells of hippocampal CA1sector of aged ra ts in order to study t he neurobiological mechanism of age-related memory defic iency.METHODS:Forty male SD rats were randomly divi ded into young and aged gr oups,with 20rats for each gro up.Morris water maze test was used to observe learning and memory b ehavior of all the rats.The ho-mogenates of rat hippocam pus was use d to determine the amount of lipid peroxide using the barbituric aci d r eactive substances assay,and the protein content was determined by sp ectro photometer.The ultrastructu ral morphology of hippocampal CA1pyram idal cells was observed using transmission electron microscope(TEM),and the morphometric al quan-tification and stereological techn ique were used to compare the number s and sizes of cell nuclei,rough endop lasmic reticulum and mitochondria betwee n the two groups.RESULTS:Compared with the young rats,the age d rats showed t he longer la-tency(38vs12s,t=8.04,P<0.01)in place navigation during the place-training experiment and less crossing numbers over the platfor m(50%vs82%,t=10.17,P<0.05)during spatial probe test.The am ount of lipid peroxide(146.2vs178.4nmol /g,t=5.61,P<0.01 ),tissue total protein(127.9vs168.8μg,t=8.25,P<0.01)a nd sedimental protein(21.1vs34.3μg,t=9.53,P<0.01)were all increased in aged rats,comp ared with those in the young rats.Alot of pyram i dal cells in 250μmCA1sector(51.9vs40.7,t=6.55,P<0.01) lost with smaller volume of nucleoli(5.34vs4.02μm 3 ,t=6.55,P<0.01).The rough endoplasmic reticulumdensity(1.4 7vs0.94μm 2 /μm 3 ,t=10.44)and mitochondria of pyramidal cells were less and smaller i n the aged rats than those in the young rats.

关 键 词：衰老 海马 CA1区 锥体细胞退行性变 自由基 空间记忆 神经生物学 细胞超微结构 

分 类 号：R339.38[医药卫生—人体生理学]