NMDA受体与鸣禽鸣唱学习记忆

N-2-甲基-D-天冬氨酸(N-methy-2-D-asparticacid,NMDA)受体,是一种分布在突触后膜上的离子通道蛋白,受突触电压和神经递质(如谷氨酸、甘氨酸、NMDA等)的双重调控,是参与学习与记忆过程的关键物质.鸣禽的鸣唱是一种习得性行为,是在特定的学习敏感期依赖听觉经验完成的.对近年来鸣禽NMDA受体与鸣禽鸣唱学习的研究进展进行了综述.     

EGCG对疲劳运动大鼠学习记忆及NMDA受体NRl亚单位表达的影响

目的：探讨表没食子儿茶素没食子酸酯（EGCG）对疲劳大鼠学习记忆及NMDA受体NRI亚单位表达的影响。方法：选取45只SPF级健康SD雄性大鼠,随机分为正常组（A组）、疲劳模型组（B组）及EGCG防护组（C组）（n=15）。建立游泳训练运动疲劳动物模型,EGCG防护组按EGCG50mg／（kg·d）容量灌胃,B组与A组按1ml（kg·d）生理盐水灌胃,每日在大鼠游泳后30min给药。运用新事物识别模型和Morris水迷宫分析各组大鼠对新事物探究能力和空间学习能力,PCR和Western blot测定NMDA受体NRlmRNA表达和蛋白表达水平。结果：B组大鼠Morris水迷宫寻找潜伏期明显高于正常对照组,且NMDA受体NRlmRNA、蛋白表达较A组低（P〈0．01）;EGCG防护组（C组）大鼠Morris水迷宫寻找潜伏期与疲劳模型组（B组）相比明显减少,同时NMDA受体NRlmRNA表达较疲劳模型组（B组）增高（P〈0．05）。结论：EGCG可增强疲劳大鼠对新事物探究及空间学习能力。     

大鼠脑发育不同时期学习记忆的变化及与NMDA受体通道动力 …

目的：研究大鼠脑发育不同时期学习记忆的变化及与ＮＭＤＡ受体通道动力学特性的关系。方法：采用学习记忆行为和离子通道动力学特性测定相结合的方法。结果：在爬杆主动回避反应中,发育早期大鼠习得和保持能力场明显强于成年大鼠。同时,发育早期大鼠训练后ＮＭ受体ｐＳ导电,而且３５ＰＳ通道开放时间和开放概率增加,３５ＰＳ通道长开放成份增多,有长ｃｌｕｓｔｅｒ开放而砀上大鼠２０Ｓ,３５ＰＳ通道关闭时间常数明显长于年龄     

不同训练方式建立大鼠空间记忆后海马结构NMDA受体表达的变化

短期强化训练能否建立可靠的空间长时记忆？用不同训练方式建立空间记忆后,大鼠海马结构NMDA受体的表达发生怎样的变化？目前尚未见明确报道。本研究应用Morris水迷宫方法分别采用以下模式对大鼠进行训练：空间长时记忆训练模式（LT组）、空间短时记忆训练模式（ST组）以及短期强化训练模式（SRT组）,对不同训练模式建立的空间记忆进行了比较,应用免疫荧光组织化学方法检测各组大鼠海马结构NMDA／NR1受体表达的变化。结果表明,Morris水迷宫训练过程中,LT和SRT组大鼠寻找站台的半均潜伏期和策略均无显著性差异：记忆检测发现,除LT组大鼠在站台所在象限的停留时间明显长于SRT组大鼠外,两组大鼠寻找站台的潜伏期和策略以及穿越站台的次数均无显著性差异。ST组大鼠海马结构NMDA／NR1的免疫反应强度与对照组相比,无显著差异。但是,LT和SRT组大鼠海马CA1区锥体细胞联及齿状回的颗粒细胞层NMDA／NR1免疫荧光反应都明显增强,两组之间比较无显著差异,但是两组分别与对照组和ST组相比均有显著性差异。上述结果提示,短期强化训练可建立与长期训练基本相同的空间长时记忆。大鼠海马结构CA1区和齿状回NMDA受体表达的增加,可能是空间长时记忆形成的机制之一。     

蛋白分子的变构作用是学习过程的基本机制

本文综述了近年在学习记忆神经机制研究中的新进展,分析了腺苷酸环化酶、NMDA受体蛋白和S₁₀₀酸性蛋白等分子发生变构作用的条件及其与学习记忆过程的关系。这些蛋白分子的变构作用既制约于条件刺激又决定于非条件刺激,两种刺激的结合就会实现较大的生物效应。这一规律表明,这些蛋白分子的变构作用是学习过程的基本机制。     

内源性甲醛参与调节记忆

甲醛是地球上进化早期阶段最早出现的同时含有C、H、O元素的最简单有机小分子之一,被发现存在于每一个真核细胞中,并参与"一碳代谢"。近期研究表明,内源性甲醛可能作为信号分子参与记忆的形成。电刺激或学习训练后,大鼠脑内甲醛含量瞬时升高,激活N-甲基-D-天冬氨酸(N-methyl-D-aspartate, NMDA)受体,促进长时程增强(long-term potentiation,LTP)或空间记忆的形成。相反,降低脑内甲醛含量后,NMDA受体不能被激活,不能形成LTP和短时记忆。在正常老年大鼠和阿尔茨海默病转基因小鼠中,脑内甲醛浓度异常升高,NMDA受体活性受到抑制,空间记忆受损。因此,维持体内生理水平的甲醛浓度对于记忆的形成与储存尤为必要。本文对内源性甲醛在学习和记忆中的生理与病理生理学功能进行了综述。     

鸟类发声学习记忆研究进展

鸟类发声学习记忆研究进展李东风,蓝书成（东北师范大学生物系神经生物学研究室长春１３００２４）学习与记忆的机制是神经科学领域中颇受重视的研究课题。鸟类的鸣啭被认为是动物语言学习记忆过程。国内外近年来的研究表明,这一过程与人类的语言学习记忆有着许多相似之...     

神经肽与学习记忆

学习和记忆是大脑高级功能之一,主要阐述了各种神经活性对学习和记忆的作用。     

NMDA受体在海马CA3区习得性TP保持中的作用

The effect of microinjection of 2-amino-5-phosphonovaleric acid (APV), a selective NMDA receptor antagonist, into the rat hippocampal CA3 area on the synaptic efficacy and related conditioned behavior during the acquisition and consolidation of discrimination learning behavior was examined. The results showed: (1) After population spike (PS) amplitude had just increased to the maximum through training i.e. learning-dependent LTP had just formed, APV 1 microliter (2 mmol/L) was injected into CA3 area, then the rats were trained during the time of efficacy of the drug in every experimental block. The result demonstrated that the PS amplitude could not be maintained at the highest level but decreased to the pre-experiment level after 8 blocks. Correct response percentage of rats could not be consolidated with further training but decreased to less than 10%. (2) After the PS amplitude had kept up at the highest level, APV 1 microliter (2 mmol/L) was injected into CA3 area, then the rats were trained during the time of efficacy of the drug in every experimental block, in which case the PS amplitude also could not be maintained at the highest level but decreased to the pre-experiment level after 14 blocks. Correlatively, when the correct response percentage of rats decreased gradually to less than 10%, the conditioned response of the animals extinguished, but its extinction speed was slower than it was in result (1). These results suggest that the NMDA receptor in CA3 area plays an important role in the maintenance of the learning-dependent long-term potentiation.     

人巨细胞病毒感染对学习记忆影响的研究进展

巨细胞病毒感染可影响儿童的学习记忆能力,是导致儿童智力残疾的主要原因之一。长期以来相关研究主要集中于巨细胞病毒先天性感染对学习记忆的影响及其机制。近年来,越来越多研究也开始关注围生期及获得性巨细胞病毒感染。本综述旨在对近期的巨细胞病毒感染致学习记忆损伤的研究现状加以概括总结。     

The biochemistry of learning and memory

Molecular and Cellular Biochemistry - An overview of some of the biochemical and molecular events involved in the process of learning and memory are presented in a short review. Two invertebrate...     

The role of acetylcholine in learning and memory

Pharmacological data clearly indicate that both muscarinic and nicotinic acetylcholine receptors have a role in the encoding of new memories. Localized lesions and antagonist infusions demonstrate the anatomical locus of these cholinergic effects, and computational modeling links the function of cholinergic modulation to specific cellular effects within these regions. Acetylcholine has been shown to increase the strength of afferent input relative to feedback, to contribute to theta rhythm oscillations, activate intrinsic mechanisms for persistent spiking, and increase the modification of synapses. These effects might enhance different types of encoding in different cortical structures. In particular, the effects in entorhinal and perirhinal cortex and hippocampus might be important for encoding new episodic memories.     

Cdk5与学习和记忆的研究进展

越来越多的证据表明,Cdk5通过与大量蛋白相互作用而在学习和记忆过程中发挥重要作用。近来,关于Cdk5的研究结果不仅证实其参与药物成瘾过程中细胞间的通路改变,且其活性与一些神经退行性疾病的发生有关。本文就Cdk5对学习和记忆的影响及其相关机制的研究进展予以综述。     

钙神经素与学习和记忆

钙神经素 (calcineurin ,CN)是一种钙依赖的蛋白磷酸酶 ,其催化亚基的基因编码具严格保守性。近年来研究证明其在学习和记忆中有重要作用 ,参与了大脑神经元突触效应的去增强、多种不同机制的长时程抑制 (LTD)、长时程增强 (LTP)、认知记忆、短期记忆向长期记忆的转换、脑老化等过程。深入研究CN参与学习和记忆的机制及其与记忆减退性疾病的关系 ,具有重要理论与实践意义     

Synaptic plasticity in learning and memory

Pavlovian conditioning has been considered as one of the principal experimental approaches to understanding such complex brain functions as learning and memory. Use-dependent alterations in synaptic efficacy are believed to form the basis for these functions. The algorithm of synapse modification proposed by D. Hebb as early as 1949 is the coincident activation of pre- and postsynaptic neurons. The present review considers the evolution of experimental protocols which were used to reveal the manifestations of Hebb-type plasticity in the synaptic inputs to neocortical and hippocampal neurons. Special attention is focused on long-term modifications of synaptic efficacy in the hippocampus as a possible neuronal mechanism of learning and the role of disinhibition in their development. The effects of various neuromodulators on hippocampal long-term potentiation are considered. It is suggested that along with their involvement in disinhibition processes these substances may control the Hebb-type plasticity through intracellular second messenger systems.     

Ubiquitin-mediated proteolysis in learning and memory

Sensitization of defensive reflexes inAplysia is a simple behavioral paradigm for studying both short- and long-term memory. In the marine mollusk, as in other animals, memory has at least two phases: a short-term phase lasting minutes and a long-term phase lasting several days or longer. Short-term memory is produced by covalent modification of pre-existing proteins. In contrast, long-term memory needs gene induction, synthesis of new protein, and the growth of new synapses. The switch from short-term (STF) to long-term facilitation (LTF) inAplysia sensory neurons requires not only positive regulation through gene induction, but also the specific removal of several inhibitory proteins. One important inhibitory protein is the regulatory (R) subunit of the cAMP-dependent protein kinase (PKA). Degradation of R subunits, which is essential for initiating long-term stable memory, occurs through the ubiquitin-proteasome pathway.