噪声对大鼠学习记忆的影响

噪声污染已无可争议地成为城市的主要环境公害之一。在噪声对学习、记忆影响程度的研究方面,国内外多数学者认为噪声主要影响学习能力和短时性记忆,而对长时性记忆没有影响或影响较小,故研究工作多集中于短时记忆功能上。目前有关噪声对学习记忆影响程度的大小、作用途径和机理仍很不清楚。本研究以噪声作用下动物电击回避反应为模型,     

糖尿病对学习记忆的影响及其机制

糖尿病是一种严重影响人类健康的疾病,糖尿病慢性脑病则是其并发症之一,主要表现为患学习与记忆能力下降。本针对糖尿病对患学习与记忆能力的影响及其机制予以概述。     

牛磺酸对小鼠耐力影响的研究

经动物实验证明 ,牛磺酸具有显著的抗疲劳 (p <0 .0 1)和抗缺氧效应 (p <0 .0 1)。对异丙肾上腺素增加的小鼠心肌耗氧有明显的抑制作用 ,可显著延长小鼠的游泳时间 (p <0 .0 1)和存活时间 (p <0 .0 1)。     

磁场作用对小鼠学习记忆的影响

目的 :探讨磁场作用对小鼠学习记忆能力的影响。方法 :应用水迷宫学习模型测定并对比 30分钟磁场处理组、1 5分钟磁场处理组和非磁场处理的正常对照组动物的空间学习记忆能力。结果 :水迷宫学习训练的实验表明 30分钟磁场处理组与正常对照组比较 ,动物到达水下平台的时间延长 ;游程增加 ;平均游速减慢 ,且均具有显著性差异 (p <0 .0 5)。 1 5分钟磁场处理组与正常对照组比较 ,动物到达水下平台的时间延长 ,且具有显著性差异 (p <0 .0 5) ;游程和平均速度与正常对照组相比无显著性差异 (p >0 .0 5)。结论 :磁场处理 30分钟或 1 5分钟损伤小鼠的空间学习记忆能力 ,且以 30分钟的磁场处理作用较强     

癫痫对大鼠学习记忆的影响及与生长抑素的相关性研究

对听源性癫痫大鼠进行迷宫训练,观察癫痫发作对大鼠光分辨学习作业的成绩以及用放射免疫分析法测定的大鼠部分脑区中生长抑素含量的影响。结果表明：（１）癫痫发作对大鼠记忆阶段有明显的抑制作用（Ｐ＜０．０１）;（２）癫痫发作后,在大鼠信息提取明显障碍的同时,其颞叶皮层、下丘脑、垂体及海马中生长抑素的含量明显增加（Ｐ＜０．０５－０．０１）。结果提示：癫痫发作影响大鼠学习记忆过程,在该过程中生长抑素含量发生改变。     

学习记忆对脑内c-fos基因表达的影响

学习记忆是人和动物重要的脑功能，大量事实表明，学习记忆过程与脑内ｃ－ｆｏｓ基因的表达密切相关。由学习记忆所诱导的ｃ－ｆｏｓ基因表达在脑内广泛分布，以皮层、海马和边缘系统为多，依学习记忆训练模型的不同，其表达时程有所差异，但一般于训练后立即或３０分钟左右出现，１～２小时左右达峰值。被动和主动回避训练、光辨别训练及味觉厌恶性条件反射训练等多种学习记忆模型均可诱导脑内ｃ－ｆｏｓ基因的表达。其他影响学习记     

杭白菊总黄酮对衰老小鼠学习记忆的影响

目的：探讨杭白菊总黄酮（TFCM）对衰老小鼠学习记忆能力及胆碱能系统的影响。方法：采用皮下注射D-半乳糖的方法制备衰老小鼠模型。ICR小鼠随机分为5组（n=10）：正常对照组,模型组,低、中、高剂量TFCM处理组。TFCM处理组于造模后第2周开始每天给予TFCM（50、100或150mg／kg）灌胃。用Morris水迷宫法检测小鼠学习记忆能力,用比色法测定血清和大脑组织中丙二醛（MDA）含量,以及超氧化物歧化酶（SOD）和乙酰胆碱酯酶（Ach E）活性。结果：与正常对照组相比,模型组学习记忆能力减退,MDA含量和Ach E活性增加,SOD活性降低。与模型组相比,中高浓度TFCM处理组（100、150mg／kg）小鼠学习记忆能力明显改善,MDA含量和Ach E活性明显降低,SOD活性增高。结论：TFEM能显著改善D-半乳糖衰老小鼠学习记忆能力,其机制可能与TFCM的抗氧化特性以及提高中枢胆碱能系统功能有关。     

硫辛酸对卵巢切除小鼠学习记忆的影响

目的:探讨硫辛酸(Lipoic acid,LA)对卵巢切除(ovariectomized,OVX)小鼠学习记忆的影响。方法:2月龄雌性昆明小鼠随机分为4组:假手术(Sham)组、OVX组、OVX+LA组、OVX+LA+左旋硝基精氨酸甲酯(L-NAME)组。建立卵巢切除模型并给药,Morris水迷宫检测各组小鼠学习记忆能力。结果:前4天定位巡航实验中,OVX组与Sham组相比,逃避潜伏期明显延长(P0.05),第5天撤除平台后,OVX组在目的象限游泳距离及时间百分比较Sham组明显缩短(P0.05);OVX+LA组与OVX组相比,逃避潜伏期明显缩短(P0.05),撤除平台后,在目的象限游泳距离及时间百分比明显延长(P0.05);OVX+LA+L-NAME组与Sham组相比,逃避潜伏期明显延长(P0.05),撤除平台后,在目的象限游泳距离及时间百分比明显缩短(P0.05)。结论:OVX损伤小鼠的学习记忆,LA可改善这种损伤,内皮型一氧化氮合酶(e NOS)抑制剂L-NAME可削弱LA的这种保护作用。     

牛磺酸对人脑神经细胞增殖,分化影响的研究

牛磺酸(taurine,C_2H_7NO_3S)的发现至今已有150多年的历史,但对它在动物体内生理功能的认识,还是在近20年内的研究中积累起来的。牛磺酸是一种结构简单,但在体内具有广泛生理功能的β-氨基酸。与其他参与蛋白质合成的氨基酸不同,通常它不做为蛋     

学习记忆相关基因研究进展

学习记忆是脑的重要功能之一,与学习记忆相关的基因很多,它们通过影响突触功能、信号转导、转录和翻译控制、能量代谢等途径进行学习记忆行为的调控。研究相关基因可为阐明学习记忆的分子机制和遗传机制奠定基础。     

Thyroid hormones, learning and memory

Thyroid hormones (THs), T3 and T4, have many physiological actions and are essential for normal behavioral, intellectual and neurological development. THs have a broad spectrum of effects on the developing brain and mediate important effects within the CNS throughout life. Insufficient maternal iodine intake during gestation and TH deficiency during human development are associated to pathological alterations such as cretinism and mental retardation. In adulthood, thyroid dysfunction is related to neurological and behavioral abnormalities, including memory impairment. Analysis of different experimental models suggests that most of the effects on cognition as a result of thyroid dysfunction rely on hippocampal modifications. Insufficiency of THs during development thus alters hippocampal synaptic function and impairs behavioral performance of hippocampal-dependent learning and memory tasks that persist in euthyroid adult animals. In the present review, we summarize the current knowledge obtained by clinical observations and experimental models that shows the importance of THs in learning and mnemonic processes.     

Incidental learning and memory for three basic tastes in food

Forty three subjects were invited under the pretence that they would take part in an experiment on hunger feelings. They came without having eaten anything that morning and received a standard breakfast containing orange juice, cream cheese on crackers and yoghurt. These products were later (when subjects returned after scoring hunger feelings during the day) used as targets amidst a set of distractors varied by adding or subtracting different amounts of two basic tastes. Orange juice was varied in sweetness and bitterness, cream cheese in sourness and bitterness and yoghurt in sweetness and sourness. The changes were made comparable by using just noticeable differences, determined in preliminary experiments with other subjects, as units of change. Two measurements of memory were compared, an absolute (indicating which were the targets) and a relative one (indicating whether the targets and distractors were more, less or equally pleasant, sweet, sour, bitter or salty as the item eaten at breakfast). Both methods showed incidental learning, but relative memory was superior. Memory differed between tastes and was partly product dependent. These experiments suggest that taste memory is tuned to detect novel and potentially dangerous stimuli rather than to remember features of earlier experienced stimuli with great precision.     

Early genomics of learning and memory: a review

The characterization of the molecular mechanisms whereby our brain codes, stores and retrieves memories remains a fundamental puzzle in neuroscience. Despite the knowledge that memory storage involves gene induction, the identification and characterization of the effector genes has remained elusive. The completion of the Human Genome Project and a variety of new technologies are revolutionizing the way these mechanisms can be explored. This review will examine how a genomic approach can be used to dissect and analyze the complex dynamic interactions involved in gene regulation during learning and memory. This innovative approach is providing information on a new class of genes associated with learning and memory in health and disease and is elucidating new molecular targets and pathways whose pharmacological modulation may allow new therapeutic approaches for improving cognition.     

Investigating the molecular mechanisms of learning and memory using Caenorhabditis elegans

Learning is an essential biological process for survival since it facilitates behavioural plasticity in response to environmental changes. This process is mediated by a wide variety of genes, mostly expressed in the nervous system. Many studies have extensively explored the molecular and cellular mechanisms underlying learning and memory. This review will focus on the advances gained through the study of the nematode Caenorhabditis elegans. C. elegans provides an excellent system to study learning because of its genetic tractability, in addition to its invariant, compact nervous system (~300 neurons) that is well-characterised at the structural level. Importantly, despite its compact nature, the nematode nervous system possesses a high level of conservation with mammalian systems. These features allow the study of genes within specific sensory-, inter- and motor neurons, facilitating the interrogation of signalling pathways that mediate learning via defined neural circuits. This review will detail how learning and memory can be studied in C. elegans through behavioural paradigms that target distinct sensory modalities. We will also summarise recent studies describing mechanisms through which key molecular and cellular pathways are proposed to affect associative and non-associative forms of learning.

     

牛磺酸对H2O2诱导的红细胞溶血率的影响

研究牛磺酸对H2O2诱导的红细胞溶血的抵抗作用的影响。实验设对照组(H2O2 生理盐水)和给药组(H2O2 牛磺酸的生理盐水溶液),将绵羊血、小鼠血、家鸡血、家兔血及人血红细胞悬液分别加入对照组和给药组,37℃水浴1h,测定吸光度,计算溶血率。结果显示,给药组的溶血率均明显低于对照组溶血率(p<0,05或p<0.01)。实验证明牛磺酸对H2O2诱导的红细胞溶血有明显的抵抗作用。     

Morris water maze: a versatile and pertinent tool for assessing spatial learning and memory

Since its development about 40 years ago (1981–2021), Morris water maze has turned into a very popular tool for assessing spatial learning and memory. Its many advantages have ensured its pertinence to date. These include its effectiveness in evaluating hippocampal-dependent learning and memory, exemption from motivational differences across diverse experimental manipulations, reliability in various cross-species studies, and adaptability to many experimental conditions with various test protocols. Nonetheless, throughout its establishment, several experimental and analysis loopholes have galvanized researchers to assess ways in which it could be improved and adapted to fill this gap. Therefore, in this review, we briefly summarize these developments since the early years of its establishment through to the most recent advancements in computerized analysis, offering more comprehensive analysis paradigms. In addition, we discuss the adaptability of the Morris water maze across different test versions and analysis paradigms, providing suggestions with regard to the best paradigms for particular experimental conditions. Hence, the proper selection of the experimental protocols, analysis paradigms, and consideration of the assay’s limitations should be carefully considered. Given that appropriate measures are taken, with various adaptations made, the Morris water maze will likely remain a relevant tool to assess the mechanisms of spatial learning and memory.     

大鼠学习记忆能力与nov基因表达的关系

采用主动回避法进行大鼠学习记忆训练 ,选出学习成绩好和差的大鼠 ,用原位杂交、免疫细胞化学结合图像分析方法观察nov基因表达的差异。结果显示 ,novmRNA和NOV蛋白阳性神经元主要分布于海马、扣带皮质和联合皮质锥体层、基底神经节和下丘脑等脑区。好成绩组NOV蛋白免疫反应最强 ,阳性细胞最多 ,差成绩组nov基因的表达比假性条件反射组的表达稍强。novmRNA的表达在各组之间无明显的差异。以上结果提示 ,nov基因可能参与学习记忆的调控过程 ,这种调控发生在NOV蛋白翻译水平。