习得性LTP中清醒大鼠海马齿状回几种氨基酸的变化

发布时间：2018-08-02 15:06

【摘要】：突触效应长时程增强(long-term synaptic potentiation，LTP)被认为和记忆有关，不少研究中表明行为学习中有LTP样的突触效应变化，LTP的幅度和维持与学习记忆能力之间存在平行关系。海马的皮层结构与啮齿类和人类的精确空间记忆有关，而海马的LTP参与记忆的形成过程。在海马齿状回(Dentate Gyrus，DG)、CA_1区和CA_3区等均可诱发LTP，目前认为其机制是，突触前膜释放Glu，通过激活NMDA受体允许Ca~(2+)进入突触后末端，继而触发了一系列与Ca~(2+)有关的生理生化反应，激活第二信使，改变膜的性质，触发了LTP的产生。AMPA受体与突触效应最初阶段增加有关；除此之外，LTP的维持需要新蛋白的合成。虽然这些研究可以表明谷氨酸以及其受体参与LTP的形成过程，但它们绝大多数是在离体海马片上进行的实验，其他的在体实验也是单独观察LTP和谷氨酸的变化，很少在动物清醒状态下同时观察LTP形成和细胞外液中的神经递质变化，尤其结合条件反射形成过程来进行的研究更是极少。另外，很多研究集中于谷氨酸，对其它的神经化学物质与LTP的关系研究得不多。因此，本实验以群体峰电位(population spike，PS)和行为正确反应率为指标，在条件反射的形成、巩固和消退过程中，测定清醒大鼠DG区谷氨酸(Glumate，Glu)、天冬氨酸(Aspartic，Asp)、谷氨酰氨(Glutamine，Gln)、牛磺氨酸(Tautine，，Tau)、甘氨酸(Glycine，Gly)、丙氨酸(Alanine，Ala)含量的变化，通过研究它们与LTP、条件行为之间的关系，探讨海马DG区参与学习记忆形成过程的神经化学机制。本实验的主要结果 1．随着大鼠条件反射的建立，Glu、Gln、Asp和Tau浓度亦随之升高。当行为训练第四天，其行为正确反应率达90％以上，此时DG区PS峰值增至最高水平，同时DG区细胞外液中Glu、Gln、Asp和Tau浓度亦达最高水平，分别为275.19±11.17％(P＜0.001)、190.25±15.34％(P＜0.01)、175.08±10.56％(P＜0.01)、170.16±9.59％(P＜0.01)。 2．在大鼠达到学会标准后对其进行巩固训练期间，兴奋性氨基酸Glu、Gln
[Abstract]:Long-term synaptic potentiation (LTP) is thought to be related to memory. Many studies have shown that there is a parallel relationship between the amplitude and maintenance of synaptic effect in behavioral learning and the ability of learning and memory. The cortical structure of the hippocampus is related to the precise spatial memory of rodents and humans, while the LTP of the hippocampus is involved in the formation of memory. LTPs can be induced in the CA1 and CA_3 regions of Dentate gyrus dentate gyrus (Dentate Gyrus gyrus DG). At present, it is considered that the mechanism is that the presynaptic membrane releases Gluand allows Ca ~ (2) to enter the postsynaptic terminal by activating the NMDA receptor, which in turn triggers a series of physiological and biochemical responses related to Ca ~ (2). Activation of the second messenger changes the properties of the membrane and triggers the production of .AMPA receptor which is related to the increase of synaptic effect at the initial stage. In addition the maintenance of LTP requires the synthesis of new proteins. Although these studies have shown that glutamate and its receptors are involved in the formation of LTP, most of them were performed on isolated hippocampal slices, and other in vivo experiments were used to observe the changes of LTP and glutamate alone. The formation of LTP and the changes of neurotransmitters in extracellular fluid are rarely observed in animal waking state, especially in combination with conditioned reflex formation. In addition, many studies have focused on glutamate, and little has been done on the relationship between other neurochemicals and LTP. Therefore, the population spike-PS and the rate of correct behavior response were taken as the indexes in the process of formation, consolidation and regression of conditioned reflex. The contents of glutamate (Glu), aspartic acid (Aspartic acid), glutamine (Glutamine glutamine), Tautine head (Tautine Tau), glycine (Glycine gly) and alanine (Alanine Ala) in DG region of conscious rats were determined, and the relationship between them and LTP, conditioned behavior was studied. To explore the neurochemical mechanism of DG region of hippocampus involved in learning and memory formation. The main results of this study were as follows: 1. With the establishment of conditioned reflex in rats, the concentrations of Glnnus asp and Tau also increased. On the fourth day of behavior training, the rate of correct behavior response was over 90%, and the peak value of PS in DG region increased to the highest level, and the concentration of Glnn Asp and Tau in extracellular fluid of DG region reached the highest level. It was 275.19 卤11.17% (P < 0.001) and 190.25 卤15.34% (P < 0.001) respectively. The excitatory amino acid GluGln was 175.08 卤10.56% (P < 0.001), 170.16 卤9.59% (P < 0.01).
【学位授予单位】：延边大学
【学位级别】：硕士
【学位授予年份】：2006
【分类号】：R33

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