A mathematical model of the retina based on neurophysiological mechanisms

基于神经生理机制的视网膜数学模型

• 批准号: 17500195
• 负责人: KAMIYAMA Yoshimi
• 金额: $ 2.39万
• 依托单位: Aichi Prefectural University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17500195/
• 关键词: Retina; Neuron Model; Neuroinformatics; Rod Photoreceptor; Retinal Ganglion Cell; Neural Spikes; 数理モデル; シミュレーション; イオンチャネル; ニューロン; 杆体

The vertebrate retina has been thought to be a window to the brain because of its accessibility and suitability for neuroscientific investigation. It is thought to be one of the few parts of the vertebrate brain where we can reasonably explain its purpose and how it works. The retina is an ideal model of an information processing neural network, describing how neurons interact to codify and process visual information. Over the last decade, we have developed mathematical models of retinal neurons based on biophysical details. These models can reveal what happens if a particular ionic current is active or inactive. One can then ask what advantages are given on the visual system by having the particular class of ion channel present in the neuron.In this study, we analyzed the underlying mechanisms of a rod photoreceptor that behaves as a bandpass filter. The simulated frequency response revealed that a single rod behaves as a bandpass filter whose characteristics are affected by the stimulus strength and frequency. We analyzed the contribution of individual ionic currents to bandpass filtering and found that the filtering of small signals is largely regulated by the calcium-dependent currents, whereas the filtering of large signals is regulated by the hyperpolarization-activated current. The major discovery was that the kinetics of the ionic currents, IK(Ca), ICl(Ca), and Ih characterize the bandpass filtering of rod signals. We also developed a stochastic model of spike generation in retinal ganglion cells. The stochastic model succeeded to reproduce precise and reliable spikes to flucutuating current injection. We found the spike timing variability was much influenced by the outward K currents, IKv and IA.

脊椎动物的视网膜一直被认为是通往大脑的窗口，因为它的可及性和适合进行神经科学研究。它被认为是脊椎动物大脑中为数不多的几个我们可以合理解释其目的和工作原理的部分之一。视网膜是信息处理神经网络的理想模型，描述了神经元如何相互作用来编码和处理视觉信息。在过去的十年里，我们已经开发了基于生物物理细节的视网膜神经元的数学模型。这些模型可以揭示如果特定的离子流是活跃的还是不活跃的，会发生什么。然后，人们可以问，在神经元中存在特定类别的离子通道，对视觉系统有什么好处。在这项研究中，我们分析了杆状光感受器作为带通滤光器的潜在机制。模拟的频率响应表明，单个杆表现为带通滤波器，其特性受激励强度和频率的影响。我们分析了单个离子电流对带通滤波的贡献，发现小信号的滤波主要受钙依赖电流的调节，而大信号的滤波则受超极化激活电流的调节。主要的发现是离子电流的动力学、Ik(Ca)、Icl(Ca)和Ih表征了棒信号的带通滤波。我们还建立了视网膜神经节细胞产生棘波的随机模型。该随机模型成功地再现了脉冲电流注入的准确和可靠的尖峰。我们发现，外向钾电流、Ikv和Ia对峰时变异性有很大影响。

项目成果

網膜秤体視細胞ネットワークのハイパスフィルタ特性のシミュレーション解析

视网膜尺度感光网络高通滤波器特性仿真分析

• 发表时间: 2006
• 作者: Yoshimi;Kamiyama;川畑 宣之;神山 斉己
• 通讯作者: 神山 斉己

A model of retinal ganglion cell based ion channel stochasticity

基于离子通道随机性的视网膜神经节细胞模型

• 发表时间: 2006
• 作者: Ryo;Matsui;Yoshimi;Kamiyama
• 通讯作者: Kamiyama

Square-wavejerkを再現する固視微動の数理モデル

再现方波急动的固定微震数学模型

• 发表时间: 2006
• 期刊: JNNS2006講演論文集
• 作者: 林田誠也;徳永憲洋;古川徹生;小濱 剛
• 通讯作者: 小濱 剛

Simulation analysis of the spatio-temporal filtering properties of the rod network by the ionic current model

离子电流模型对棒网络时空滤波特性的仿真分析

• 发表时间: 2005
• 期刊: ARVO 2005 Annual Meeting
• 作者: Kamiyama;Y.
• 通讯作者: Y.

A mathematical model of retinal rod photo receptor network

视网膜杆光感受器网络的数学模型

• 发表时间: 2007
• 作者: Yoshimi;Kamiyama;K.Tokunaga;Yoshimi Kamiyama;T.Minatohara;Yoshimi Kamiyama;T.Furukawa;Yusuke Miyamoto
• 通讯作者: Yusuke Miyamoto