MULTINEURONAL SIGNALING BY THE VERTEBRATE RETINA

这项研究项目旨在详细了解眼睛是如何 向大脑发送视觉信息。的功能研究 视网膜已经初步决定了单个神经元和 它们的突触连接，虽然相对鲜为人知的是如何 一个特定细胞的活动与其他细胞的活动在时间上是相关的。然而， 大脑中的视觉中枢利用同时放电的模式 在大量的视网膜神经节细胞中检测到 我们视觉环境的重要特征。因此，最终的目标是 一项拟议的工作是准确地确定视网膜是如何编码 神经节细胞内电活动模式的视觉场景 一层。这项工作的重点是视觉信息的表示 一群神经元，而不是单个细胞。 在这些实验中，老虎火蜥蜴的视网膜被放置在 在玻璃表面上嵌入了许多金属微电极，覆盖了 面积约0.2毫米(2)。视网膜神经节细胞紧密排列。 接近电极阵列，使得每个位置记录 由附近少数神经元产生的细胞外动作电位。因此， 一个人可以同时监测多达100个电信号 神经节细胞。视网膜是由感官输入刺激的， 将计算机显示器的图像投射到感光层上。 这些方法将用于下列具体项目： (1)大鼠神经节细胞功能特性的研究 视网膜。这项研究将确定细胞之间的数量比例 不同的响应类型，无论它们是否在空间上排列 有组织的模式，以及它们的分布如何与 他们可以从视觉刺激中提取信息。 (2)不同放电模式之间的相关性研究 神经节细胞。这些神经元通常与它们的 活动，并参与协同开火的模式，只有 多电极记录观察。这些分布式射击 图案传达的是视觉信息？ (3)研究视觉刺激的特征可能是什么 从记录的神经节细胞棘波序列估计。我们的目标是 构建一个可以解释视网膜输出的算法以提供 视觉输入的重建。这将揭开结构的面纱 视网膜编码，并提示后续视觉中心如何环路 可能执行类似的特征检测任务。 这些研究将揭示集体作用的重要方面 视网膜的环路。研究结果将提供一个更好的理解 我们如何看待，以及大脑如何表达和处理信息。 最终，这可能会导致检测和治疗的改进 视觉缺陷，以及在遥远的未来，对视觉的发展 可以模拟视网膜功能的假体。

This research project aims for a detailed understanding of how the eye signals visual information to the brain. Functional investigations of the retina have primarily determined the properties of single neurons and their synaptic connections, while comparatively little is known about how a given cell's activity correlates in time with that of others. Yet the visual centers in the brain draw on the pattern of simultaneous firing in a large population of retinal ganglion cells in order to detect important features of our visual environment. Thus, the ultimate goal of the proposed work is to determine precisely how the retina encodes a visual scene by the patterns of electrical activity in the ganglion cell layer. The work focuses on the representation of visual information in a population of neurons, rather than individual cells. In these experiments, the isolated retina of a tiger salamander is placed on a glass surface with many embedded metal microelectrodes, covering an area of about 0.2mm(2). The retinal ganglion cells lie in close proximity to the electrode array, such that each site records extracellular action potentials generated by a few nearby neurons. Thus, one can monitor simultaneously the electrical signals from up to 100 ganglion cells. The retina is stimulated with sensory input by projecting an image from a computer monitor onto the photoreceptor layer. These methods will be used in the following specific projects: (1) A survey of the functional properties of ganglion cells in the retina. This study will determine the numerical proportions among cells of different response types, whether they are arranged in a spatially organized pattern, and how their distribution relates to the type of information they can extract from the visual stimulus. (2) A study of correlations between the firing patterns of different ganglion cells. These neurons are often strongly correlated in their activity, and participate in modes of concerted firing that can only be observed by multielectrode recording. Do these distributed firing patterns convey visual information? (3) An investigation of how features of the visual stimulus might be estimated from the recorded ganglion cell spike trains. The goal is to construct an algorithm that can interpret the retinal output to provide a reconstruction of the visual input. This will uncover the structure of the retinal code and suggest how circuits at subsequent visual centers might perform similar tasks of feature detection. These studies will reveal important aspects of collective function in the circuits of the retina. The results will provide a better understanding of how we see, and how the brain represents and processes information. Ultimately, this may lead to improvements in detecting and treating visual deficiencies, and, in the far future, to the development of visual prostheses that can emulate the function of the retina.