本文關(guān)鍵詞： 視覺假體 視網(wǎng)膜神經(jīng)節(jié)細胞 FCM模型 電刺激響應(yīng) 相平面分析 仿真　出處：《天津醫(yī)科大學(xué)》2011年碩士論文　論文類型：學(xué)位論文

【摘要】：研究目的： 視網(wǎng)膜中,視網(wǎng)膜神經(jīng)節(jié)細胞是唯一能夠形成動作電位,并投射于中樞神經(jīng)的視網(wǎng)膜組成部分。它的生理特性和電刺激響應(yīng)活動,對用于視覺恢復(fù)的視覺假體的研制具有重要的意義。本論文應(yīng)用Fohlmeister, Coleman和Miller提出的被稱之為FCM模型的視網(wǎng)膜神經(jīng)節(jié)細胞模型,來研究模型對輸入不同電刺激的響應(yīng)活動,并用相平面圖的方法來分析模型中各離子通道對動作電位產(chǎn)生的作用,這將為我們進一步探究視網(wǎng)膜神經(jīng)節(jié)細胞的功能,研究人工視覺假體提供支持。 研究方法： 1.基于MATLAB平臺,應(yīng)用FCM模型對視網(wǎng)膜神經(jīng)節(jié)細胞的放電活動進行仿真,并進行分析。同時,在FCM模型仿真的基礎(chǔ)上,研究鈣離子電導(dǎo)的變化,以及鈣離子通道和鈣離子激活的鉀通道在視網(wǎng)膜神經(jīng)節(jié)細胞放電過程中的作用。 2.選取不同的電刺激方式,分析不同大小的直流電刺激和不同大小不同頻率正弦電刺激對于神經(jīng)節(jié)細胞放電過程的影響；并計算視網(wǎng)膜神經(jīng)節(jié)細胞動作電位在軸突上的傳播速度。 3.用相平面圖的分析方法,來深入分析動作電位產(chǎn)生過程當中,各個離子電導(dǎo)變化情況,以及在脈沖放電過程中,動作電位的變化。 研究結(jié)果： 1.通過分析FCM模型,發(fā)現(xiàn)鈉離子通道,鈣離子通道,以及三種鉀離子通道在鉗定電壓下的變化(如圖3.1),而且它們在動作電位形成過程中所起作用各不相同,作用階段也不相同。而通過分析FCM模型發(fā)現(xiàn),鈣離子通道對FCM模型膜電位的頻率和大小都有特殊的影響。 2.FCM模型放電脈沖頻率隨著直流電刺激的變大而變大,產(chǎn)生的動作電位有明顯的大小變化。隨著正弦刺激頻率的增大,FCM模型放電形式由爆發(fā)放電形式逐漸變?yōu)橛幸?guī)律的節(jié)律放電。而隨著正弦刺激幅度的增大,FCM模型放電頻率增大,直到變?yōu)闊o阻尼振蕩運動。 3.FCM模型的放電活動,在相平面圖中有不同的表現(xiàn)。 研究結(jié)論： 1.鈣離子通過電壓門控鈣離子通道和以及鈣離子激活的鉀離子通道,對FCM模型的放電活動及動作電位波形產(chǎn)生影響。這進一步從模型仿真的角度解釋了視網(wǎng)膜神經(jīng)節(jié)細胞中鈣離子在動作電位波形,以及放電活動等生理活動中的作用。 2.由于不同的電刺激活動,對FCM模型的影響各不相同。因此研究不同刺激對FCM模型的影響,這對于以后視覺假體刺激大小的選擇,具有重要意義。 3.本論文中,相平面圖分析方法是一種有效分析FCM模型放電活動中動作電位形成過程的一種方法,能夠直觀地觀察動作電位各個不同形成階段的特點,以及脈沖放電過程中各動作電位的不同。
[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.

【學(xué)位授予單位】：天津醫(yī)科大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2011
【分類號】：R774

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本文編號：1553658