NEURAL CONNECTIONS OF RETINA - FINE STRUCTURE OF INNER PLEXIFORM LAYER
NEURAL CONNECTIONS OF RETINA - FINE STRUCTURE OF INNER PLEXIFORM LAYER
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DOI：
10.1101/sqb.1965.030.01.039
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发表时间：
1965-01-01
期刊：
影响因子：
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通讯作者：
BOYCOTT, BB
中科院分区：
文献类型：
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作者：
DOWLING, JE;BOYCOTT, BB
进一步了解脊椎动物视网膜和一般中枢神经系统的基本要求之一是发现更多关于神经细胞突触组织的信息。我们对视网膜组织的了解，大部分来自对高尔基体方法制备的组织的研究（Cajal，1894; Polyak，1941）。高尔基体固定的材料使得对细胞类型进行分类和跟踪它们的过程成为可能。这种材料不能可靠地显示神经细胞形成的突触接触;为此，需要电子显微镜。不幸的是，通常很难将电子显微镜下看到的过程与光学显微镜下看到的结构的几何形状相关联。脊椎动物视网膜中细胞类型的数量是有限的，并且细胞和它们的突起通常局限于特定的层。这解决了电子显微镜下的一些定向问题，并使视网膜成为这种分析的有利材料。本报告将主要涉及视网膜内丛状层的连接，在内丛状层中有三种类型的细胞具有突起：第一，双极细胞，其终止于此并将信息传递给神经节细胞;第二，神经节细胞，其树突延伸到内丛状层中，可能与双极细胞终末接触;第三，无长突细胞，其突起在整个内网状层横向延伸。这些最后的细胞因缺乏轴突而被卡哈尔称为无长突细胞，长期以来一直是一个谜。大多数研究者称之为”联合”细胞（参见Polyak，1941），但关于它们的突触联系或生理作用，尚无确切的信息。内核层中多达四分之一的细胞可能是无蛋白质。对高尔基体固定的视网膜的研究也使早期的研究者将内网状层的细胞分为几个亚型（Cajal，1894; Polyak，1941）。因此，波利亚克描述了四种主要的双极细胞：扁平双极细胞、刷子双极细胞、拖把双极细胞和侏儒双极细胞。然而，在电子显微镜下，我们无法区分细胞的亚型。例如，所有的双极
One of the basic requirements for a further understanding of the vertebrate retina, and of the central nervous system in general, is to discover more about the organization of the synapses of nerve cells. Most of what we know of retinal organization has come from the study of tissue prepared by the method of Golgi (Cajal, 1894; Polyak, 1941). Golgi-fixed material makes it possible to classify types of cells and to follow the course of their processes. Such material does not show reliably the synaptic contacts a nerve cell makes; for this, electron microscopy is needed. Unfortunately, it is usually difficult to correlate the processes seen under the electron microscope with the geometry of the structures seen by the light microscope. The number of cell types in the vertebrate retina is limited, and the cells and their processes are usually confined to specific layers. This solves some of the problems of orientation under the electron microscope and makes the retina favorable material for such an analysis. This report will be concerned primarily with the connections of the inner plexiform layer of the retina.There are three cell types with processes in the inner plexiform layer: first, the bipolar cells, which terminate there and pass information to the ganglion cells; second, the ganglion cells, whose dendrites extend into the inner plexiform layer, presumably to contact the bipolar cell terminals; and third, the amacrine cells, whose processes extend laterally throughout the inner plexiform layer. These last cells, called amacrines by Cajal because of their lack of an axon, have long been an enigma. Most investigators speak of them as" associational" cells (see Polyak, 1941), but no firm information has been available as to their synaptie contacts or physiological role. As many as one quarter of the cells in the inner nuclear layer may be amaerines. The study of retinas fixed by the method of Golgi had also led earlier investigators to classify the cells of the inner plexiform layer into several sub-types (Cajal, 1894; Polyak, 1941). Thus, Polyak describes four major varieties of bipolar cells: the flat, brush, mop, and midget bipolars. However, in the electron microscope, we have not been able to distinguish sub-types of cells. For example, all the bipolar