FCM模型的相平面图分析及其电刺激响应

发布时间：2018-03-01 21:33

本文关键词： 视觉假体视网膜神经节细胞 FCM模型电刺激响应相平面分析仿真　出处：《天津医科大学》2011年硕士论文　论文类型：学位论文

【摘要】：研究目的：视网膜中,视网膜神经节细胞是唯一能够形成动作电位,并投射于中枢神经的视网膜组成部分。它的生理特性和电刺激响应活动,对用于视觉恢复的视觉假体的研制具有重要的意义。本论文应用Fohlmeister, Coleman和Miller提出的被称之为FCM模型的视网膜神经节细胞模型,来研究模型对输入不同电刺激的响应活动,并用相平面图的方法来分析模型中各离子通道对动作电位产生的作用,这将为我们进一步探究视网膜神经节细胞的功能,研究人工视觉假体提供支持。研究方法： 1.基于MATLAB平台,应用FCM模型对视网膜神经节细胞的放电活动进行仿真,并进行分析。同时,在FCM模型仿真的基础上,研究钙离子电导的变化,以及钙离子通道和钙离子激活的钾通道在视网膜神经节细胞放电过程中的作用。 2.选取不同的电刺激方式,分析不同大小的直流电刺激和不同大小不同频率正弦电刺激对于神经节细胞放电过程的影响；并计算视网膜神经节细胞动作电位在轴突上的传播速度。 3.用相平面图的分析方法,来深入分析动作电位产生过程当中,各个离子电导变化情况,以及在脉冲放电过程中,动作电位的变化。研究结果： 1.通过分析FCM模型,发现钠离子通道,钙离子通道,以及三种钾离子通道在钳定电压下的变化(如图3.1),而且它们在动作电位形成过程中所起作用各不相同,作用阶段也不相同。而通过分析FCM模型发现,钙离子通道对FCM模型膜电位的频率和大小都有特殊的影响。 2.FCM模型放电脉冲频率随着直流电刺激的变大而变大,产生的动作电位有明显的大小变化。随着正弦刺激频率的增大,FCM模型放电形式由爆发放电形式逐渐变为有规律的节律放电。而随着正弦刺激幅度的增大,FCM模型放电频率增大,直到变为无阻尼振荡运动。 3.FCM模型的放电活动,在相平面图中有不同的表现。研究结论： 1.钙离子通过电压门控钙离子通道和以及钙离子激活的钾离子通道,对FCM模型的放电活动及动作电位波形产生影响。这进一步从模型仿真的角度解释了视网膜神经节细胞中钙离子在动作电位波形,以及放电活动等生理活动中的作用。 2.由于不同的电刺激活动,对FCM模型的影响各不相同。因此研究不同刺激对FCM模型的影响,这对于以后视觉假体刺激大小的选择,具有重要意义。 3.本论文中,相平面图分析方法是一种有效分析FCM模型放电活动中动作电位形成过程的一种方法,能够直观地观察动作电位各个不同形成阶段的特点,以及脉冲放电过程中各动作电位的不同。
[Abstract]:The purpose of the study is:
In the retina, retinal ganglion cell is the only form of the action potentials, and projected on the central nervous system of retinal part. The physiological characteristics and electroresponse activities. It has important significance to the development of visual prosthesis for visual recovery. This paper used Fohlmeister, Coleman and Miller model of retinal ganglion cells in the known for the FCM model, to study the model response to input activities of different electric stimulation, and by phase plane method to analyze the ion channel model of action potential, it will be for us to further explore the function of retinal ganglion cells, the research of visual prosthesis to provide support.
Research methods:
1. based on the MATLAB platform, the application of FCM model on discharge activity of retinal ganglion cells was simulated and analyzed. At the same time, based on FCM model, changes of calcium ion conductance, and calcium channel and calcium activated potassium channels in ganglion cells in retinal nerve discharge process.
2., we choose different electrical stimulation methods to analyze the effect of DC stimulation with different sizes and sinusoidal electrical stimulation with different size and frequency on the discharge process of ganglion cells, and calculate the propagation speed of action potentials of retinal ganglion cells on axons.
3., we use phase plane analysis method to analyze the change of ionic conductance in action potential generation and the change of action potential during pulse discharge.
The results of the study:
1. through the analysis of the FCM model, sodium channel, calcium channel, and three kinds of potassium ion channels in the changes of the voltage clamp (Figure 3.1), and their action potentials in the formation process of the role played by the different stage is not the same. And through the FCM model analysis found that all there are special effects of frequency and size of calcium channel on the membrane potential of FCM model.
The firing frequency of 2.FCM model with the DC electrical stimulation became larger, action potential generation has changed significantly. With the increase of the size of the sinusoidal stimulus frequency, FCM model of discharge form has gradually changed from a burst discharge form of rhythmic discharge. With the sine amplitude increases, the FCM model of the discharge frequency increases. Until the undamped oscillatory motion.
The discharge activity of the 3.FCM model has different performance in the phase plane diagram.
The conclusions are as follows:
1. calcium ions via voltage-gated calcium channels and calcium activated potassium channel, the influence of discharge activity and action potential waveform of the FCM model. The simulation model further from the point of view to explain the calcium ion in retinal ganglion cells in the action potential waveform, and firing physical activity.
2., because of different electrical stimulation activities, the influence of FCM model is different. Therefore, the influence of different stimuli on FCM model is studied, which is of great significance for the selection of visual prosthesis stimulus size.
3., phase plane analysis is a effective way to analyze the formation process of action potential in FCM model. It can intuitively observe the characteristics of different stages of action potential and the difference of action potentials during pulse discharge.

【学位授予单位】：天津医科大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R774

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