神经元放电活动分岔分析.doc

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神经元放电活动的分岔分析
摘要
神经元是神经系统的基本结构和功能单元, 在神经信息处理过程中起着关键的作用。虽然神经系统各不相同，但大多数神经元都具有许多相似的特征：比如各种离子通道、丰富的非线性现象以及作为信息载体的膜电位等。神经信息主要依靠神经元丰富的放电节律模式进行编码，因而研究神经细胞通过内在参数变化或外部激励条件改变时展现的放电节律模式以及各种模式之间的相互转迁就有着及其重要意义。
本文应用非线性动力学的分岔理论、相平面分析、快慢动力学分析和数值模拟等方法，针对神经元ML模型、HR模型以及Chay模型，系统地研究了神经元的放电行为及放电模式间相互转迁的动力学机制。这些方法也可以应用于其它类型神经元，或用于发现新的放电模式，并对今后的神经电生理实验有一定的理论指导作用。
关键词：神经元 峰放电 簇放电 分岔 相平面分析 快慢动力学分析
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Bifurcation Analysis on Neuronal Firing Activities
Abstract
As the fundamental structural and functional unit of the nervous system, neuron plays an extremely vital role in the neural information processing．Although nervous systems are quite different, many fundamental features of neurons are common to most of neurons, such as ion channels, rich nonlinear phenomenon and the membrane potential as the carrier of information. Various firing patterns are related to different stimuli, which mean that firing patterns carry corresponding neural information, so it is meaningful to study different firing activities owing to internal parameters or external stimulations, as well as the transitions between different firing patterns.
In this dissertation, based on the bifurcation theory of nonlinear dynamics, the phase plane analysis, the fast-slow dynamics analysis and the numerical simulation, we deeply study on different firing activities and dynamics mechanism of transitions between different firing patterns. These methods and results in this dissertation can be applied to different types of neurons, and also may give an instructive guidance to the observation and analysis of neuronal firing activities, and hence will promote the development of both nonlinear dynamics and neuroscience.
Key Words: neuron, spiking, bursting, bifurcation, phase plane analysis, fast-slow dynamics analysis
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第一章 引言
研究背景
二十世纪后半叶，非线性科学作为研究非线性现象共性的基础学科，获得了前所未有的发展，其与量子论、相对论一起被誉为二十世纪自然科学中的“三大革命”。非线性科学的研究不仅具有深远的科学意义，而且具有广泛的应用前景。
大量的研究表明，非线性动力学研究的分岔是非线性系统最重要而又最基本的特性，几乎在所有涉及非线性科学