Analysis of spatio-temporarl mechanisms on outer plexiform layer in retina by the multichannel microprobe electrodes array chip

我们开发了多通道微探针电极阵列芯片，用于记录视网膜对光的神经反应，并建立了视网膜神经元的数学模型，以分析记录的光诱导反应所涉及的视网膜机制。采用气液固选择性生长方法在Si（111）衬底上制备了微探针电极阵列（MEA）芯片原型。原型MEA可以检测到对白色闪光的特征和对单色刺激的敏感性与视网膜光电图（ERG）一致的光响应。我们还证明了在狭缝光的刺激下，局部ERG响应的变化是由MEA得到的。为了分析测得的ERG反应所涉及的视网膜内部机制，我们利用生理工程技术建立了视网膜神经元和视网膜神经回路模型。在ERG反应中与b波形成密切相关的水平细胞和双极细胞模型，用它们的离子机理进行了数学描述。这使我们能够分析光响应与神经元内离子机制之间的关系。这些结果表明，所开发的MEA芯片作为一种新的测量工具，可以应用于视网膜神经记录，视网膜神经元模型将在理解视网膜视觉信息预处理方面发挥重要作用。

We have developed multichannel microprobe electrode array chips for recording neural responses to light from retina, and mathematical model of retinal neurons to analyze retinal mechanisms involved in the recorded light-induced responses.Prototypes of the microprobe electrode array(MEA) chip have been fabricated on Si(111) substrates by selective Vapor-Liquid-Solid(VLS) growth method. The prototype MEA could detect light responses whose characteristics to a white flash and sensitivities to monochromatic stimulus were consistent with photopic electoretinogram(ERG). We also demonstrated that the changes of localized ERG responses were obtained with stimulus of slit light by the MEA.In order to analyze inner retinal mechanisms involved in the measured ERG responses, we have developed models of retinal neuron and the retinal neural circuit by physiological engineering technique. The models of horizontal cell and bipolar cells which is closely related to form b-wave in ERG responses were described mathematically by their ionic mechanisms. It is allow us to analyze the relationship between light responses and the ionic mechanisms in their neuron.These results suggest that the developed MEA chip is applicable to retinal neural recordings as a new measurement tool, and the models of retinal neuron would play a role to understand visual information preprocessing of retina.