被动运动相关的海马神经信号解析与信息编码模型研究

发布时间：2018-07-10 09:31

本文选题：海马 + theta节律　；参考：《清华大学》2012年博士论文

【摘要】：海马是空间认知的重要脑区。关于大鼠海马与运动关系的研究由来已久。以往的研究集中于自由运动，通过鉴别两种theta节律及其与运动模式的关系，对海马神经元的发放模式获得了一些认识。在动物导航时可以通过本体感觉、视觉流、前庭输入得到自身运动的信息。被动运动能够切断本体感觉通路，为我们研究其速度感知提供了很好的范式。本文围绕空间认知中的速度信息编码问题，以被动运动模式为研究范式，在实验和建模两个方面做了较为细致的研究。主要包括四个部分：1）被动运动实验范式和研究方法的建立；2）被动运动模式下海马场电位的特点和分类；3）被动运动模式下海马神经元锋电位的特点及与场电位的关系；4）海马等相关脑区空间认知及速度编码的模型探讨。通过比较大鼠在线性轨道中自由移动和被动运动海马的theta节律证实两者具有不同特性。结果显示，在被动运动模式下，theta节律的频率与被动运动的速度成正相关，theta节律的频率和幅度明显降低；然而，硫酸阿托品对theta节律无阻滞作用，提示被动运动时的theta节律与自由运动时一样，都属于非毒蕈碱型乙酰胆碱能通路的theta I。theta I一直被认为与自主运动相关联，被动运动并非自主运动，在此情况下海马中也存在theta I，，这为theta I的功能和作用提出了新的问题。在对被动运动时的锋电位分析后发现，被动运动时有部分神经元与速度有一定的相关性；与自由运动相比，被动运动时theta节律对神经元活动的调制有所减弱，锋电位与场电位相干在theta频段降低，这可能反映了单个神经元和集群活动之间协同性的降低；与场电位的结果类似，被动运动的方向对海马神经元活动无影响，提示与方向相关的编码在海马之外。综合实验观察结果，我们提出在被动运动时theta节律频率的降低以及锋电位和场电位协同性降低可能是由于本体感觉缺失引起感知速度降低而造成的。从这个假设出发，本论文试图在理论上进行探讨，提出了不依赖于感知速度误差的扩展速度调控振荡模型，分别在概念和网络层次进行了讨论，目的是将实验中的观察结果与现有的认识统一起来，理解速度信息在大脑相关脑区发挥的作用。
[Abstract]:Hippocampus is an important brain area of spatial cognition. The relationship between hippocampus and exercise in rats has been studied for a long time. Previous studies focused on free movement. By distinguishing the two theta rhythms and their relationship with motility patterns, we have gained some understanding of the distribution model of hippocampal neurons. In the navigation of animals, the information of their own motion can be obtained by means of proprioceptive sensation, visual flow and vestibular input. Passive motion can cut off the proprioceptive pathway, which provides a good paradigm for us to study the velocity perception. This paper focuses on the encoding of velocity information in spatial cognition, taking passive motion mode as the research paradigm, and doing more detailed research in two aspects: experiment and modeling. There are four parts: 1) Establishment of experimental paradigm and research methods of passive motion 2) characteristics and classification of hippocampal field potential in passive motion mode 3) characteristics of hippocampal neuron spike potential and its relationship with field potential in passive motion mode; 4) the model of spatial cognition and speed coding in hippocampus and other related brain regions. By comparing the theta rhythms of the free and passive movement of the hippocampus in the linear orbit of the rat, it is proved that the two have different characteristics. The results showed that there was a positive correlation between the frequency of theta rhythm and the velocity of passive motion. However, atropine sulfate had no effect on theta rhythm. It is suggested that the theta rhythm in passive motion is similar to that in free exercise, and that theta I.thetaI, which belongs to the non-muscarinic acetylcholinergic pathway, is always considered to be associated with autonomous movement, and that passive motion is not autonomous. In this case, theta I also exists in the hippocampus, which raises new questions about the function and function of theta I. After analyzing the spike potential of passive motion, it is found that some neurons in passive motion have a certain correlation with velocity, and the modulation of theta rhythm to neuron activity is weaker in passive motion than in free motion. The coherence of spike potential and field potential decreased in theta band, which may reflect the decrease of synergy between single neuron and cluster activity, and similar to the result of field potential, the direction of passive movement had no effect on hippocampal neuron activity. This indicates that the direction-related coding is outside the hippocampus. Based on the experimental results we suggest that the decrease of theta rhythm frequency and the synergistic reduction of spike potential and field potential during passive motion may be due to the loss of proprioceptive sensation and the decrease of sensing speed. Based on this assumption, this paper attempts to discuss theoretically, and proposes an extended velocity control oscillation model, which is independent of the perceptual velocity error, and discusses the concept and network level, respectively. The aim of this study is to unify the experimental results with existing knowledge and to understand the role of speed information in the brain-related brain regions.
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2012
【分类号】：R338

【共引文献】