年龄对SAMP8小鼠不同脑区NSF含量的影响

采用免疫印迹技术检测NSF蛋白和内参蛋白GAPDH在SAMP8小鼠背侧海马、腹侧海马、额叶、顶叶和嗅球的表达。结果显示在背海马、额叶和顶叶中,13月龄SAMP8小鼠NSF的相对含量显著高于5月龄(Ps<0.05),且13月龄背侧海马NSF含量也高于9月龄鼠(P<0.05),而在腹海马和嗅球NSF的含量在各个年龄段间差异无统计学意义(Ps>0.05)。以上结果提示在正常衰老过程中,SAMP8小鼠NSF含量在脑内某些区域呈现年龄相关性增高。     

长期口服阿卡波糖对SAMP8小鼠背海 马synaptotagminⅠ的影响

利用免疫组化法检测长期口服阿卡波糖对SAMP8小鼠背海马突触蛋白synaptotagminⅠ（SytⅠ）表达的影响。结果显示,SytⅠ在背海马CA1、CA3区和齿状回各层均有表达。老年对照组小鼠背海马各区SytⅠ的相对含量显著高于青年对照组（Ps<0.05）。阿卡波糖处理组小鼠背海马各区SytⅠ的相对含量显著低于同龄对照组（Ps<0.05）。上述结果提示长期口服阿卡波糖可减轻SAMP8小鼠背海马年龄相关性SytⅠ增加的水平。     

中年CD-1小鼠背海马syntaxin1水平的改变

应用免疫组化技术检测13月龄(中年)和5月龄CD-1小鼠背海马突触前蛋白syntaxin 1的表达水平。结果显示,13月龄小鼠齿状回、CA1及CA3区各层syntaxin 1的相对含量较5月龄均显著下降。表明中年CD-1小鼠背海马syntaxin 1含量全面下调。     

中年CD-1小鼠背海马syntaxin 1水平的改变

应用免疫组化技术检测13月龄(中年)和5月龄CD-1小鼠背海马突触前蛋白syntaxin 1的表达水平.结果显示,13月龄小鼠齿状回、CA1及CA3区各层syntaxin 1的相对含量较5月龄均显著下降.表明中年CD-1小鼠背海马syntaxin 1含量全面下调.     

胚胎晚期暴露脂多糖对中年CD-1小鼠背侧海马 SUMO-3含量的影响

为探讨胚胎晚期暴露细菌脂多糖(LPS)的中年CD-1小鼠背侧海马的类泛素化蛋白(SUMO-3)含量有无年龄相关性改变。采用免疫组织化学技术检测LPS暴露组和对照组CD-1小鼠背侧海马DG区、CA1区和CA3区各亚层的SUMO-3表达。结果表明,两组间各区各亚层的SUMO-3含量无明显差异。     

CD-1小鼠海马H3K9三甲基化水平的年龄化改变 及其与认知功能改变的相关性研究

探讨年龄对CD-1小鼠海马组蛋白H3K9三甲基化(H3K9me3)含量的影响及其与空间学习记忆能力改变的相关性。结果发现,18月和12月龄鼠在放射状水迷宫中学习期和记忆期的潜伏期、错误数均高于6月龄鼠(P_s0.05);18月龄鼠学习期及记忆期的错误数还高于12月龄鼠(P_s0.05)。18月龄鼠海马DG和CA1区H3K9me3水平高于12月龄鼠(P_s0.05),12月龄鼠也高于6月龄鼠(P_s0.05)。DG和CA1区H3K9me3相对含量与学习期的潜伏期和错误数以及记忆期错误数呈正相关(P_s0.05),而CA3区H3K9me3相对含量与学习期和记忆期的错误数、潜伏期之间无明显相关性(P_s0.05)。以上结果提示,CD-1小鼠年龄相关空间学习记忆损害可能与海马组蛋白H3K9me3升高有关。     

中老年期CD-1小鼠海马突触蛋白Arc含量改变及其与认知功能下降的相关性研究

探究中老年CD-1小鼠海马突触蛋白Arc含量的改变及其与空间学习记忆能力下降的相关性。选取3月龄和15月龄CD-1小鼠各10只（雌雄各半）,用Morris水迷宫和免疫组织化学法分别检测其空间学习记忆能力和海马Arc蛋白相对含量。与3月龄相比,15月龄鼠在Morris水迷宫学习期游泳路程延长（F_(1,16)= 5.338, P＜0.05）,记忆期靶象限内游泳路程百分比下降（F_(1,16)=78.013, P＜0.01）,海马CA1和CA3区Arc水平增加（P＜0.05）。相关分析显示15月龄鼠海马CA1、CA3和DG区Arc相对含量与学习期游泳路程正相关（P＜0.05）,CA3、DG区Arc含量还与记忆期靶象限游泳路程百分比负相关（P＜0.05）。中老年CD-1小鼠海马Arc含量呈亚区特异性增高,可能涉及其空间学习记忆损害。     

白藜芦醇对快速老化鼠肝脏抗氧化能力的影响

分析白藜芦醇对快速老化鼠(SAMP/8)肝脏抗氧化能力的影响.将4月龄雄性SAMP/8鼠随机分为模型组和白藜芦醇低、中、高剂量组,4月龄正常老化SAMR/1鼠为正常对照组.对照组及模型组用生理盐水灌胃,白藜芦醇治疗组给予25、50和100mg/kg白藜芦醇灌胃.连续给药8周,测定各组小鼠肝组织超氧化物歧化酶(SOD)、丙二醛(MDA)的含量,以HE染色进行肝组织形态学观察.结果表明:白藜芦醇各剂量组能提高SAMP/8鼠肝组织SOD活性(P<0.01),降低MDA含量(P<0.01),且能改善肝组织形态结构,尤以高剂量组效果显著.因此,白藜芦醇能显著提高SAMP/8鼠肝组织的抗氧化能力,具有一定的延缓衰老作用.     

中老年CD-1小鼠海马Staufen蛋白含量改变及其与认知功能减退的相关性研究

探讨中老年CD-1小鼠海马Staufen（Stau）蛋白含量的改变及其与空间学习记忆功能减退之间的相关性。选取3月龄（青年）和15月龄（中老年）CD-1小鼠各10只（雌雄各半）。采用Morris水迷宫评估空间学习记忆能力,用免疫组织化学技术检测海马Stau蛋白的相对含量。结果发现,与3月龄小鼠相比,15月龄鼠在Morris水迷宫中学习期游泳路程显著延长（P<0.01）,记忆期靶象限游泳路程百分比显著降低（P<0.05）,且海马CA1区和CA3区Stau蛋白含量显著升高（P<0.05）。相关性分析显示,15月龄小鼠CA1区、CA3区Stau蛋白含量与学习期游泳路程呈正相关（P<0.05）,CA3区Stau蛋白含量与记忆期靶象限路程百分比呈负相关（P<0.05）。以上结果提示中老年CD-1小鼠海马Stau蛋白含量呈亚区特异性增加,且可能与海马相关性空间学习记忆的损害有关。     

年龄对SAMP8小鼠新物体再认能力的影响

探讨年龄对快速老化敏感小鼠8(SAMP8)短期再认记忆能力的影响.结果表明,与3及7月龄小鼠比较,11月龄SAMP8小鼠的新物体再认能力增强.与对照的11月龄SAMR1(快速老化抵抗小鼠1)小鼠比较,11月龄SAMP8小鼠的新物体再认能力也增强.这种记忆的增强不受性别因素的影响. 这些结果提示在衰老过程中,SAMP8小鼠的新物体再认能力增强.     

仔猪海马结构及其周围皮质内生长抑素mRNA的分布

用原位杂交组织化学法研究了５头仔猪海马结构及其周围皮质内生长抑素ｍＲＮＡ的分布。结果表明生长抑素ｍＲＮＡ主要分布于海马的始层和齿状回的多形层，偶见于海马的辐射层和锥体细胞层，此外，在内溴区和海马旁回内也见到标记细胞，主要位于深层。     

胚胎晚期母体暴露细菌脂多糖对中年CD-1子鼠背海马synaptotagmi Ⅳ的影响

对胚胎晚期母体腹腔注射细菌脂多糖或生理盐水,利用免疫组化法对CD-1中年子鼠背海马CA1、CA3区和齿状回各层突触蛋白synaptotagmin IV的表达进行研究。结果显示synaptotagmin Ⅳ在背海马各层均有表达。与盐水对照组相比,细菌脂多糖处理组子鼠背海马CA1、CA3区各层和齿状回分子层的synaptotagmin Ⅳ含量显著增高(Ps<0.05)。结果表明胚胎晚期母体暴露细菌脂多糖可显著增加中年子鼠背海马Syt IV表达。     

Regional variation of extracellular space in the hippocampus

The factors responsible for the unusual susceptibility of the hippocampus to seizures and ischemic cell damage are not well understood. The CA1 pyramidal subfield of the hippocampus is particularly vulnerable to seizure activity and damage after ischemia. The possibility was examined that regional differences exist in extracellular volume, which might influence neuronal excitability and response to injury in the hippocampus. CA1 stratum pyramidale exhibited an exceptionally low extracellular volume fraction (EVF) of 0.12, whereas the EVFs of CA3 and dentate were considerably higher--0.18 and 0.15, respectively. The EVF of CA1 stratum pyramidale was reversibly reduced by 30 percent when the extracellular potassium concentration was raised from 3.5 to 8.5 mM, a procedure that induced spontaneous electrographic seizures in CA1. Thus there are regional variations in the properties of the extracellular space in the hippocampus that might underlie the propensity of the CA1 region to develop seizures and to suffer damage after ischemia.     

青春期双酚A暴露对老年CD-1小鼠海马 齿状回Synaptotagmin 1含量的影响

探讨青春期双酚A暴露对老年期齿状回Synaptotagmin 1（Syt 1）含量的影响。结果显示,18月龄CD-1小鼠齿状回Syt 1相对含量显著高于6月龄小鼠（Ps<0.05）;青春期双酚A暴露高剂量小鼠齿状回Syt 1表达量显著高于同年龄对照小鼠（Ps<0.05）,雌鼠更明显。这些结果进一步支持小鼠海马Syt 1呈年龄相关性增加的结论,青春期双酚A暴露可加剧这种增加。     

Associative induction of posttetanic and long-term potentiation in CA1 neurons of rat hippocampus

Electrical stimulation of fibers in the stratum radiatum causes an excitatory postsynaptic potential in CA1 neurons of the hippocampus. Other excitatory inputs to or direct depolarization of these CA1 neurons during stimulation of the stratum radiatum caused a subsequent increase in the excitatory postsynaptic potential. This enhancement was characterized as a brief potentiation (2 to 3 minutes, similar to posttetanic potentiation) and a long-term potentiation (presumed to be involved in learning and memory). These potentiations are probably induced by an interaction of the postsynaptic cell or other presynaptic terminals with the test presynaptic terminals.     

Pattern separation in the human hippocampal CA3 and dentate gyrus

Pattern separation, the process of transforming similar representations or memories into highly dissimilar, nonoverlapping representations, is a key component of many functions ascribed to the hippocampus. Computational models have stressed the role of the hippocampus and, in particular, the dentate gyrus and its projections into the CA3 subregion in pattern separation. We used high-resolution (1.5-millimeter isotropic voxels) functional magnetic resonance imaging to measure brain activity during incidental memory encoding. Although activity consistent with a bias toward pattern completion was observed in CA1, the subiculum, and the entorhinal and parahippocampal cortices, activity consistent with a strong bias toward pattern separation was observed in, and limited to, the CA3/dentate gyrus. These results provide compelling evidence of a key role of the human CA3/dentate gyrus in pattern separation.     

Dentate gyrus NMDA receptors mediate rapid pattern separation in the hippocampal network

Forming distinct representations of multiple contexts, places, and episodes is a crucial function of the hippocampus. The dentate gyrus subregion has been suggested to fulfill this role. We have tested this hypothesis by generating and analyzing a mouse strain that lacks the gene encoding the essential subunit of the N-methyl-d-aspartate (NMDA) receptor NR1, specifically in dentate gyrus granule cells. The mutant mice performed normally in contextual fear conditioning, but were impaired in the ability to distinguish two similar contexts. A significant reduction in the context-specific modulation of firing rate was observed in the CA3 pyramidal cells when the mutant mice were transferred from one context to another. These results provide evidence that NMDA receptors in the granule cells of the dentate gyrus play a crucial role in the process of pattern separation.