The mathematical model of retinal neurons based on ionic currents and calcium mechanisms

基于离子电流和钙机制的视网膜神经元数学模型

基本信息

批准号：
10650407
负责人：
USUI Shiro
金额：
$ 2.18万
依托单位：
Toyohashi University of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650407/
关键词：
retina horizontal cell bipolar cell ganglion cell ionic current intracellular calcium system simulation 数理モデル

项目摘要

In the neuroinformatics study of the retina, each retinal cell has been mathematically modeled based on their ionic current mechanisms. In order to reconstruct full model of the retina by integrating individual cell models, it is essential to introduce the synaptic transmission model. Because intracellular calcium ions is involved closely in the synaptic transmission mechanisms, a model of the synaptic transmission including calcium mechanisms has to be constructed. In the present study, a quantitative model for horizontal cell and bipolar cell which are secondary order neurons, and ganglion cell which is the output neuron of retina, and their synaptic mechanisms including calcium mechanisms have been developed.A retinal horizontal cell of rabbit was modeled based on the ionic current and the generating mechanisms of repetitive spikes was analyzed by using the model. The results suggest that the spikes are generated by a calcium current and a delayed rectifier potassium current in the horizontal cell. We constructed the model of a ganglion cell based on recent physiological evidence. The model included seven nonlinear ionic currents and one linear leakage current. The model could well reproduce responses under voltage champ and current clamp condition and spikes with blocked KィイD1+ィエD1 currents.Models of transmitter induced currents and synaptic terminal including calcium system in retinal ON-center bipolar cell were constructed. By integrating these models, an ON-center bipolar cell where spatial distribution of ionic channels is not uniform were modeled. Coupling coefficients between the soma and the synaptic terminal and light responses were analyzed using the model. The results suggested that the bipolar have easy to conduct signal to both direction and that dynamics of the light responses was strongly affected by ionic current of synaptic terminal.

在视网膜的神经信息学研究中，每个残留细胞都是根据其离子电流机制对数学建模的。为了通过整合单个细胞模型来重建视网膜的完整模型，至关重要的是引入合成传输模型。由于细胞内钙离子与合成传递机制紧密涉及，因此必须构建包括钙机制的合成传递模型。在本研究中，用于水平细胞和双极细胞的定量模型是二级神经元，神经节细胞是视网膜的输出神经元，以及它们的合成机制，包括钙机制。兔子的视网膜水平细胞基于重复的尖峰进行了模型，并基于重复的尖峰进行了建模。结果表明，尖峰是由钙电流和水平细胞中延迟的整流钾电流产生的。我们根据最近的物理证据构建了神经节细胞的模型。该模型包括七个非线性离子电流和一个线性泄漏电流。该模型可以很好地在电压冠军和当前的夹具条件下重现响应，并具有阻塞的KYI D1+IYE D1电流的尖峰。构建了发射机诱导电流的模型和包括视网膜中心双极细胞中钙系统的突触终端。通过整合这些模型，对离子通道的空间分布的中心双极细胞进行了建模。使用模型分析了SOMA和突触终端之间的耦合系数和光反应。结果表明，双极性易于向方向传导信号，并且光反应的动力学受到突触末端的离子电流的强烈影响。