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

在视网膜的神经信息学研究中，每个视网膜细胞都以其离子电流机制为基础进行了数学建模。在按顺序重建视网膜的完整模型中，它是一个必要的引入synaptic transmission model的集合。因为内钙离子体是在synaptic transmission Mechanisms中封闭的，一个模型of the synaptic transmission包括calcium Mechanisms必须被构造。在目前的研究中，用于水平细胞和双极细胞的定量模型是次级神经元，而恒河细胞的输出是视网膜神经元，以及它们的合成机制，包括钙机制已经被开发出来。兔子的视网膜水平细胞是基于离子电流和重复峰值的生成机制是通过使用该模型分析的。该研究的结果是，尖峰是由一个钙电流和一个延迟的记录器钙电流产生的。我们根据最近的生理学证据构建了一个基于Ganglion细胞的模型。模型包括七个非线性电离电流和一个线性泄漏电流。模型could well reproduce responses under voltage champ and current clamp condition and spikes with blocked K-D1 + J-D1 currents。Models of transmitter induced currents and synaptic terminal including calcium system in retinal ON-center bipolar cell were constructed。通过综合这些模型，一个在中心的双极细胞，在那里的离子通道的空间分布不是统一的模型。在Soma和synaptic terminal之间的耦合协同效应和光响应已经用模型分析了。该研究的结果建议，即双极很容易将信号传递到两个方向，而光响应的动力学被电离电流的合成终端的影响很大。

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.