神经元放电模型再探及听觉中枢的频率整合作用

发布时间：2018-04-25 03:31

本文选题：神经元 + 动作电位　；参考：《南方医科大学》2010年硕士论文

【摘要】： 神经系统的放电活动主要表现为神经元产生和传输动作电位脉冲的过程,神经信息编码是通过神经元放电脉冲的时间节律来反映的。目前以MP模型为基础的神经元模型,仅模仿神经元有无输出,而对最重要的什么时候产生动作电位并没有解释。本研究的目的是通过建立神经元放电数学模型,解释神经元是如何以产生动作电位的时间序列编码输入信息,并将模型应用在听觉中枢的信息传递中,在这个基础上探讨了听觉中枢的频率整合作用。本研究回顾了神经生物学和听觉生理学的基础知识,对神经元放电模型进行了分类,并分析以往神经元放电模型的优缺点,为更好的研究生物神经元信息处理机制做理论铺垫。在分析神经元放电机制的基础上,提出了神经元放电数学模型,在Matlab7.0.1平台上分别从单通道和八通道进行仿真,得到系列动作电位,结果显示所模拟的动作电位密度分布与生理实验所采集的数据能较好吻合,验证了神经元以动作电位的时间特性来编码输入信息的特征。最后介绍了耳蜗基底膜的振动方式以及行波理论,并通过计算机仿真实验证实听觉中枢频率整合的特点：1、听觉中枢频率整合过程中的延时反应特性具有放大信号和消除噪声的作用；滤波器的阶数变化影响滤波器延时时间,并随滤波器阶数的增加而变长。不同输入信号频率、滤波器的采样频率和中心频率对其没有影响,这表明听觉中枢频率整合过程中的延时反应与滤波器的固有特性没有关系,是听觉中枢频率整合过程中所特有的。2、滤波后信号最大幅值出现的位置,与输入信号的频率以及通道的中心频率有关,验证了生理学上蜗底对高频声音进行编码,蜗顶对低频声音进行编码特性。3、当对不同通道的滤波器进行权重设置,整合后能变化其中心频率,这使得神经元传送信息变得多样化。本研究为基于数理模型的神经中枢工作机制研究、以及模糊理论的研究和应用提供新的思路。
[Abstract]:The firing activity of the nervous system is mainly the process of producing and transmitting action potential pulses, and the neural information coding is reflected by the time rhythm of the firing pulses of the neurons. At present, the neuron model based on MP model only imitates whether the neuron has output or not, but does not explain when the most important action potential is generated. The purpose of this study is to establish a mathematical model of neuronal discharge, to explain how neurons encode input information in time series of action potential generation, and to apply the model to the transmission of information in auditory center. On this basis, the frequency integration of auditory center is discussed. In this study, the basic knowledge of neurobiology and auditory physiology was reviewed, and the neural discharge models were classified, and the advantages and disadvantages of the previous models were analyzed, which paved the way for better research on the mechanism of biological neuron information processing. On the basis of analyzing the mechanism of neuronal discharge, a mathematical model of neuronal discharge is proposed. A series of action potentials are obtained by simulation on Matlab7.0.1 platform from single channel and eight channels, respectively. The results show that the simulated action potential density distribution is in good agreement with the data collected from physiological experiments, which verifies the characteristics of neurons encoding input information by the time characteristics of action potential. Finally, the vibration mode and traveling wave theory of the basal membrane of cochlea are introduced. It is proved by computer simulation experiment that the characteristic of frequency integration of auditory center is: 1, the delay response characteristic in the process of frequency integration of auditory center has the function of amplifying signal and eliminating noise, the change of filter order affects the delay time of filter, And it becomes longer with the increase of filter order. The sampling frequency and center frequency of the filter have no effect on the input signal frequency, which indicates that the delay response in the integration of the auditory central frequency is not related to the inherent characteristics of the filter. The location of the maximum amplitude of the filtered signal is related to the frequency of the input signal and the central frequency of the channel, which verifies that the bottom of the cochlea encodes the high-frequency sound on the bottom of the cochlea in physiology. The cochlea top encodes the low-frequency sound. 3. When the filters of different channels are weighted, the central frequency of the cochlea can be changed after integration, which makes the transmission information of neurons become diversified. This study provides a new idea for the study of the work mechanism of neural center based on mathematical model and the research and application of fuzzy theory.
【学位授予单位】：南方医科大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R338

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