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首页> 外文学位 >Properties of ON- and OFF-center beta cell somatic and dendritic mosaics in cat retina.
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Properties of ON- and OFF-center beta cell somatic and dendritic mosaics in cat retina.

机译：猫视网膜中ON和OFF中心β细胞的体细胞和树突状镶嵌的特性。

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摘要

It is widely believed that the array of beta (X) cell dendritic field centers constitutes the sampling grid for the X cell component of the retinal "neural image", with the dendritic field as the sampling aperture and the cell spacing as the sampling distance. Dendrites of either ON- or OFF-center X cells cover the whole retina. Hence, the X cell part of the "neural image" is sampled by two sets of cells. This dissertation aimed to improve our understanding of the role of beta cells in image representation, and addressed the following three major questions: (1) What are the morphological characteristics of the dendritic trees, and how do they depend upon retinal location? (2) How are the dendritic trees of a homogeneous beta cell mosaic arranged relative to one another, and what does this imply about the spatial arrangement of retinal sampling? (3) Are the beta cell ON- and OFF-center subsets spatially dependent and, if so, what is the spatial relationship?; A combined approach including retrograde Neurobiotin transport, Voronoi-Delaunay analysis, and computer modeling was employed to answer these questions. The basic results are: (1) The shape of dendritic field and soma was found to be elliptical, with a major-to-minor axis ratio of 1.3{dollar}sim{dollar}1.4. (2) The orientation of the major dendritic axis was found to run with the gradient of local cell density, and point roughly towards the area centralis. (3) The dendritic coverage factor for either ON- or OFF-center beta cells was found to be about 1.7 across the retina. (4) Soma lattices were found to be always less regular than corresponding dendritic mosaics, and become more regular as the eccentricity increases. (5) The regularity of dendritic mosaics was found to remain fairly unchanged across the retina, with the CV of the adjacent neighbor distribution being 0.17 which is similar to the CV of cat cone lattices. (6) The ON- and OFF-center beta cell lattices have a precise relationship to one another in the form of a spatial shift of about one half cell spacing.; The results suggest that cat beta (X) cells, with two homogeneous dendritic mosaics as regular as cat cone lattices and positioned precisely with respect to one another, are optimized for coding the highest resolution spatial information.
机译：普遍认为，β（X）细胞树突场中心的阵列构成了视网膜“神经图像”的X细胞成分的采样网格，其中树突场为采样孔，细胞间隔为采样距离。中心X细胞或中心X细胞的树突覆盖整个视网膜。因此，“神经图像”的X单元部分是由两组单元采样的。本文旨在增进我们对β细胞在图像表征中的作用的理解，并提出以下三个主要问题：（1）树突树的形态特征是什么，它们如何依赖于视网膜的位置？ （2）均匀的β细胞镶嵌的树突状树如何相对排列，这对视网膜采样的空间排列意味着什么？ （3）beta单元的ON和OFF中心子集在空间上是否相关，如果有，空间关系是什么？结合使用包括逆行神经生物素转运，Voronoi-Delaunay分析和计算机建模的组合方法来回答这些问题。基本结果是：（1）发现树突场和躯体的形状为椭圆形，长轴与短轴之比为1.3 {dol} sim {dollar} 1.4。 （2）发现树突长轴的方向与局部细胞密度的梯度有关，并大致指向中央区域。 （3）发现中心ON或中心OFF的β细胞在整个视网膜上的树突覆盖因子约为1.7。 （4）发现索玛晶格总是比相应的树突状镶嵌不规则，并且随着偏心率的增加而变得更规则。 （5）发现树突状镶嵌体的规则性在整个视网膜上保持基本不变，相邻邻居分布的CV为0.17，与猫锥晶格的CV相似。 （6）以中心为中心和中心为中心的β细胞晶格彼此之间具有精确的关系，其形式为大约一半细胞间距的空间位移。结果表明，具有两个均匀的树突状镶嵌（如猫锥状晶格一样规则且相对于彼此精确定位）的cat beta（X）细胞经过优化，可用于编码最高分辨率的空间信息。

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  • 作者

    Zhan, Xue (James).;

  • 作者单位

    Northwestern University.;

  • 授予单位 Northwestern University.;
  • 学科 Biology Neuroscience.; Biology Anatomy.; Engineering Biomedical.
  • 学位 Ph.D.
  • 年度 1996
  • 页码 160 p.
  • 总页数 160
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 神经科学;生物形态学;生物医学工程;
  • 关键词

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