Microcircuitry of the cat retina.
Microcircuitry of the cat retina.
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DOI：
10.1146/annurev.ne.06.030183.001053
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发表时间：
1983
影响因子：
13.9
通讯作者：
P. Sterling
中科院分区：
文献类型：
--
作者：
P. Sterling
作为一种从视觉图像中提取信息的装置，脊椎动物的视网膜在其范围、可靠性和紧凑性方面是无与伦比的。视网膜上的信号传递比集成数字电路慢6个数量级。因此，生物结构的优势必然来自其基本元素的多样性和它们之间微妙的联系。视网膜神经元的突触接触最初是由Dowling & Boycott（1966）系统描述的，这五类神经元中的每一类现在已知有多种类型，猫的总数约为60种。在电子显微镜下已经识别出了涉及这些神经元约三分之一的特定局部电路。大约三分之一的类型的生理反应也被记录下来，关于神经递质的证据，或者至少是突触的迹象，也积累了大约三分之一。这些发现有力地支持了由Lettvin和Maturana在20世纪60年代提出的视网膜功能的某些概念。他们提出，视网膜的功能“不是传递图像中明暗点对点分布的信息，而是在每个点上分析图像……任意上下文……（Maturana et at 1960）。他们认为，这些“上下文”中的每一个都对应于特定大小和形状的神经节细胞对局部图像执行的某些操作（Lettvin et al 1961）。这个基于对青蛙的研究的想法，一度似乎不适用于猫，因为猫被认为只有一个“简单”的视网膜，只有中心环绕型神经节细胞。这里将要回顾的后续研究已经为这只猫确立了这一观点的有效性。
As a device for extracting information from a visual image, the vertebrate retina is unparalleled in its range, reliability, and compactness. Signaling in the retina is slower by six orders of magnitude than in an integrated digital circuit. The advantage of the biological structure must therefore derive from the variety of its fundamental elements and from the subtlety of their connections. Each of the five major classes of retinal neuron, whose synaptic contacts were first described systematically by Dowling & Boycott (1966), is now known to have multiple types, totaling in the cat about 60. Specific local circuits involving about one-third of these neurons have been recog nized in the electron microscope. Physiological responses have also been documented for about one-third of the types, and evidence regarding the neural transmitter, or at least the sign of the synapse, has accumulated also for about one-third. These discoveries have abundantly supported certain concepts of retinal function developed in the 1960s by Lettvin & Maturana. The function of the retina, they proposed, "is not to transmit information about the point to-point distribution of light and dark in the image, but to analyze this image at every point in terms of ... arbitrary contexts ... " (Maturana et at 1960). Each of'these "contexts," they suggested, corresponds to some operation on the local image performed by a ganglion cell of particular size and shape (Lettvin et al 1961). This idea, based on studies of the frog, seemed for a time inapplicable to the cat, which was thought to have a "simple" retina with only center-surround type ganglion cells. Subsequent studies to be reviewed here have firmly established for the cat the validity of this idea.