年龄对C57BL/6小鼠在不同空间性学习记忆能力的影响

探讨C57BL/6小鼠在辐射状六臂水迷宫(RAWM)和Morris水迷宫(MWM)中是否有一致性学习记忆能力减退,以及两任务中的成绩是否相关.结果表明,在RAWM和MWM中,老年小鼠的空间性学习记忆能力均下降,但对每个小鼠而言,两个空间任务间的成绩几乎没有关联(MWM中的潜伏期仅与RAWM中的学习成绩弱相关,r=0.45～0.49).这些结果表明RAWM和MWM都是优秀的空间学习记忆任务,对检测小鼠的年龄相关性学习记忆功能减退均敏感,但个体完成两个任务的成绩不一致,提示在探讨记忆减退机制时最好两个任务并用.     

中年ICR小鼠学习记忆损害与血清甲状腺素的关系

研究中年ICR小鼠在新物体再认任务和六臂辐射状水迷宫(RAWM)中的学习记忆能力变化及其与血清甲状腺素(TH)的相关性。结果表明,新物体再认试验中12月龄与6月龄ICR小鼠间的成绩无显著性差异;RAWM中,12月龄小鼠较6月龄小鼠空间学习记忆能力减退;12月龄小鼠血清TH水平(FT3,FT4)低于6月龄小鼠,且FT3水平既与小鼠的空间性学习能力相关,又与记忆能力相关,而FT4仅与空间性学习能力相关。这些结果提示血清TH水平下降可能参与了中年ICR小鼠空间学习记忆能力减退。     

胚胎期暴露氰戊菊酯对中年CD-1小鼠 空间学习记忆能力的影响

本研究旨在探讨胚胎期暴露氰戊菊酯对中年CD-1小鼠空间学习记忆能力的影响。利用六臂辐射状水迷宫任务检测胚胎期暴露氰戊菊酯组与暴露乳剂的对照组13月龄CD-1小鼠的空间学习记忆能力。结果表明,在辐射状水迷宫任务的学习期和记忆期中,氰戊菊酯组的错误数和潜伏期均显著高于对照组(Ps<0.05)。因此,胚胎期暴露氰戊菊酯可加速中年CD-1小鼠年龄相关性空间学习记忆能力减退的出现。     

昆明小鼠早期空间认知功能损害具有任务特异性

利用六臂辐射状水迷宫(RAWM)和Morris水迷宫(MWM)任务检测中年和青年昆明小鼠的空间性认知功能差异.结果表明,在RAWM和MWM任务中,12.5月和5月龄鼠均表现出一定的学习效应,即随测试天数的增加而成绩变好.在RAWM中,12.5月龄小鼠学习记忆能力较5月龄小鼠减退,而在MWM中,2个年龄段的小鼠的学习记忆能力无显著差异.以上结果提示昆明小鼠可能早在12.5月龄时就开始出现轻度空间认知功能损害.RAWM可能比MWM更适合小鼠轻度认知功能损害的检测.     

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。     

吉林地产紫苏油、松籽油和核桃油对小鼠学习与记忆能力的影响

目的：观察不同种类的不饱和脂肪酸对小鼠学习能力和记忆能力的影响,以了解其是否具有提高学习与记忆能力的作用.方法用不同剂量的紫苏油、松籽油、核桃油连续给小鼠灌胃6周,然后采用跳台实验检测小鼠的学习能力和记忆能力.结果与对照组相比,低、中、高剂量的紫苏油、松籽油、核桃油在小鼠的学习能力和记忆能力的测定指标即错误次数上有显著性差异（P〈0.05）.结论在本次实验剂量范围内,不同剂量的紫苏油、松籽油、核桃油可以提高小鼠学习能力和记忆能力,且有明显的剂量-效应关系.     

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。     

路标影响高体鳑鲏的空间学习与记忆

使用采集于湖北省大冶市保安湖的16尾性成熟的雌性高体鳑鲏为实验对象,利用T形迷宫装置,研究在有一个标记物和无标记物情况下高体鳑鲏的空间学习与记忆能力。结果表明高体鳑鲏具有很好的空间学习与记忆能力。而且在有一个标记物(视觉提示)存在时高体鳑鲏学习能力较强,这可能揭示出不同的学习策略对记忆形成快慢有影响,路标的视觉提示作用能够起到比自身方向感更强烈的刺激记忆形成的作用。     

茶叶浸提液对小鼠学习记忆能力影响的初步研究

茶对人体具有降三高、减肥、提神、防老年痴呆症等功效。然而学校大多数同学在口渴的情况下选择喝茶叶水人数比例只占12.3%。因此,研究喝茶可能提高记忆能力、饮茶是否对青少年智力发展具有帮助具有意义。本文通过3项实验,分别分析了不同配比的茶叶浸提液中茶多酚的含量测定,不同加工方式的茶叶浸提液对小鼠学习记忆能力的影响,不同浓度的茶叶浸提液对小鼠学习记忆能力的影响,最终喝茶对青少年智力发展具有一定作用的结论。     

昆明小鼠年龄相关性物体位置再认能力减退

探讨昆明小鼠物体位置再认能力的年龄、性别效应.结果表明,10 min和24 h延迟试验中21月龄小鼠较12月龄和6月龄小鼠物体位置再认记忆有显著性减退,且主要归因于雌鼠;即刻试验中,老年雄鼠有物体位置再认即刻记忆减退.以上结果提示,老年雌性昆明小鼠有长时性和遥远性物体位置再认记忆减退.     

酸樱桃汁对D-半乳糖致衰老小鼠学习记忆功能的影响

目的检测酸樱桃汁对D-半乳糖致衰老小鼠模型学习记忆功能的影响.方法颈背部皮下注射D-半乳糖120 mg/（kg·d^-1）连续56 d建立亚急性衰老模型,同时灌胃给予不同剂量的酸樱桃汁进行治疗,治疗8周后,分别采用跳台实验、Morris水迷宫检测小鼠的学习记忆能力.结果跳台法检测结果显示：酸樱桃汁能延长D-半乳糖致衰老模型小鼠的潜伏期,减少错误次数;Morris水迷宫实验结果显示：酸樱桃汁能使D-半乳糖致衰老模型小鼠平均潜伏期明显缩短,跨过平台次数显著增加.结论酸樱桃汁能有效提高D-半乳糖致衰老小鼠的学习记忆能力.     

Glucocorticoids can induce PTSD-like memory impairments in mice

Posttraumatic stress disorder (PTSD) is characterized by a hypermnesia of the trauma and by a memory impairment that decreases the ability to restrict fear to the appropriate context. Infusion of glucocorticoids in the hippocampus after fear conditioning induces PTSD-like memory impairments and an altered pattern of neural activation in the hippocampal-amygdalar circuit. Mice become unable to identify the context as the correct predictor of the threat and show fear responses to a discrete cue not predicting the threat in normal conditions. These data demonstrate PTSD-like memory impairments in rodents and identify a potential pathophysiological mechanism of this condition.     

Forms of memory failure

Memory may fail in a variety of ways. Patients with Korsakoff's syndrome demonstrate global memory deficits similar to those seen in patients with early progressive dementia. Korsakoff's patients, however, may recall rules and principles for organizing information and can gain access to their previously acquired knowledge (semantic memory), whereas recent memory may be grossly impaired. In contrast, dementia patients may have little access to previously acquired knowledge and therefore have great difficulty in organizing and encoding ongoing events. These contrasting forms of memory failure have implications for understanding the structure and mechanisms of memory and learning, particularly the relationship between episodic and semantic memory, as well as the development of therapeutic strategies for cognitive impairments.     

Hippocampectomy and behavior sequences

Four monkeys with bilateral hippocampal lesions were trained to respond sequentially to visual stimuli, presented with an automated discrimination apparatus. Two different sequential tasks were presented. The experimental animals were significantly inferior on both problems to six control animals. Since no impairment appeared on simple visual discriminations presented with intertrial intervals from 5 seconds to 6 minutes, simple sensory deficits and "short-term" memory impairments appear unlikely. The results strengthen the interpretation that bilateral hippocampal lesions interfere with the acquisition of those behaviors which involve the execution of sequential responses.     

衰老对斑马鱼呼吸代谢和游泳行为的影响

以模式生物斑马鱼作为实验对象,首先从躯体形态和繁殖能力上对6月龄与30月龄斑马鱼的特征进行了区分,而后分别比较了6月龄和30月龄斑马鱼在昼夜节律、应激行为和呼吸代谢方面的差异,研究衰老对斑马鱼代谢和行为的影响。结果显示:30月龄斑马鱼脊柱弯曲,并且在产卵量、受精率、孵化率和成活率等方面均低于6月龄斑马鱼,显示出明显的衰老特征。6月龄斑马鱼昼夜间的游泳行为具有明显的节律性,与30月龄斑马鱼相比,其白天活动量大,夜晚静息,昼夜间游泳行为具有显著差异。当遭受驱逐刺激后,6月龄斑马鱼的快速游泳距离、快速游泳时间和平均游泳速度均高于30月龄斑马鱼(P 0. 05);当遭受光照刺激后,6月龄斑马鱼的快速游泳距离和平均游泳速度高于30月龄斑马鱼(P 0. 05)。应激行为实验结果表明:衰老斑马鱼的应激游泳能力显著低于年轻斑马鱼。30月龄斑马鱼的标准代谢率(SMR)、最大代谢率(MMR)和代谢范围(MS)低于6月龄斑马鱼(P 0. 05),与应激游泳行为的差异一致。繁殖、代谢和应激游泳行为是鱼类重要的生理活动,研究衰老与年轻斑马鱼的生理行为,有助于进一步理解衰老对机体生理功能的影响,并为深入探究衰老对斑马鱼代谢和行为影响的内在机制奠定基础。     

实葶葱种子老化过程生理生化变化的研究

以国内仅分布于新疆的实葶葱种子为材料,研究了不同贮藏年份的种子经过老化处理后种子发芽力、相对电导率、丙二醛含量、超氧化物歧化酶活性和过氧化物酶活性的变化。结果表明,随着老化程度的加深,种子发芽力逐渐降低,实葶葱种子贮藏2~3年的活力最佳。随着自然老化和人工老化的加深电导率呈上升趋势,丙二醛含量及超氧化物歧化酶活性呈下降趋势。过氧化物酶活性在不同老化程度种子内无明显差异。实葶葱种子老化过程中种子活力降低可能是由于细胞膜系统受损和有毒物质积累造成的。     

老化和磁场处理对大白菜种子生理生化指标的影响

为研究大白菜种子老化后的生理生化变化以及磁处理对种子活力的影响,采用高温高湿的人工环境和人工磁场,测定种子老化后活力指标的变化。结果表明:4个大白菜品种随着老化时间的增加,发芽率、发芽势、发芽指数及活力指数都呈下降趋势,发芽势的下降幅度要大于发芽率的下降幅度。老化种子浸出液的电导率随老化时间的延长而逐渐增加,超氧化物歧化酶、过氧化物酶及过氧化氢酶的活性逐渐降低。经过磁场处理后的老化种子的各项活力指标的变化趋势与未经磁场处理的大体一致,但变化幅度明显变小,特别在老化后期,这种趋势更加明显。表明磁场处理在一定程度上可提高大白菜种子抗老化能力,品种间存在一定差异。     

Tau suppression in a neurodegenerative mouse model improves memory function

Neurofibrillary tangles (NFTs) are the most common intraneuronal inclusion in the brains of patients with neurodegenerative diseases and have been implicated in mediating neuronal death and cognitive deficits. Here, we found that mice expressing a repressible human tau variant developed progressive age-related NFTs, neuronal loss, and behavioral impairments. After the suppression of transgenic tau, memory function recovered, and neuron numbers stabilized, but to our surprise, NFTs continued to accumulate. Thus, NFTs are not sufficient to cause cognitive decline or neuronal death in this model of tauopathy.     

THE PROBLEMS OF AGING AND OF VASCULAR DISEASES

The increase in death rate with increasing age over that at the age of ten accounts for over a million deaths each year in the United States. To what extent these deaths are due to the aging process remains to be determined, but the progressive loss of resistance to nearly all diseases appears to play a large role even in youth and middle life. Since loss of resistance to disease, as well as loss of ability, seems to result from an underlying aging process we may look upon aging as constituting our greatest medical problem. Second in importance to the aging problem is that of the vascular and renal diseases, since these are involved in nearly 50 per cent. of the deaths after the age of ten (in addition to the effect of aging). Until more is known about aging and vascular diseases we are not justified in predicting what can or can not be done about them. A new experimental method in which healthy animals of different ages are killed by a known measurable cause offers possibilities for determining the nature of the aging process. Our two outstanding medical problems are being neglected largely because of the lack of funds to support both the long-term research and the raising of old animals needed for adequate investigation in this field. New endowments as well as changes in the policies of existing foundations are urgently needed.     

Hydration aging of nuclear waste glass

The aging of simulated nuclear waste glass by contact with a controlled-temperature, humid atmosphere results in the formation of a double hydration layer penetrating into the glass and in the formation of minerals on the glass surface. The hydration process described here provides insight into the aging kinetics of naturally occurring glasses and also suggests that simulated aging reactions are necessary for demonstrating that nuclear waste forms can meet projected Nuclear Regulatory Commission requirements.