THE REPRESENTATION OF THE VISUAL-FIELD IN PARVICELLULAR AND MAGNOCELLULAR LAYERS OF THE LATERAL GENICULATE-NUCLEUS IN THE MACAQUE MONKEY
THE REPRESENTATION OF THE VISUAL-FIELD IN PARVICELLULAR AND MAGNOCELLULAR LAYERS OF THE LATERAL GENICULATE-NUCLEUS IN THE MACAQUE MONKEY
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DOI：
10.1002/cne.902260408
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发表时间：
1984-01-01
影响因子：
2.5
通讯作者：
VANESSEN, D
中科院分区：
文献类型：
--
作者：
CONNOLLY, M;VANESSEN, D
本文构建了猕猴膝状背外侧核（LGN）各层的二维图，并以此作为比较层大小、形状和地形组织的基础。llgn电生理调查的地形数据显示在所有6层的地图上。中央视觉在LGN中有明显的过度代表。然而出乎意料的是，在大多数LGN层的部分上，视觉表示是各向异性的。线性放大系数（毫米沿着层流表面每度的视野）是不相等的所有方向从一个给定的点在视野。LGN的小细胞分裂和大细胞分裂的视觉表现在其对中央视觉的强调和各向异性上有所不同。为了确定个体变异的程度，从其他7个半球的LGN制备了层流图。层流图的形状在LGN之间变化很大，从接近圆形到高度椭圆形，但每层的表面积相对恒定。地形组织，通过绘制视盘在LGN层上的表现，以及通过纹状皮层中顺行和逆行示踪剂注射的标记来确定，显示出显著的个体差异。LGN和纹状皮层的视觉表征在拓扑上是相互倒置的；基因皮质连接的建立可能涉及纤维的系统交叉。结果与其他研究的信息进行比较，以估计皮层神经元与LGN神经元在不同偏心率下的比例。每个LGN神经元的皮质神经元总数约为。平均是130，但它会延伸到。apprx。10倍的范围，从远外围的< 100到。1000在中央窝。估计4A层和4c层细胞的数量。每个细胞层神经元较小，并且在30-240的范围内延伸稍窄，而层数为4c . α。每个大细胞神经元的神经元数目在45-7000之间变化更大。
2-Dimensional maps of individual layers of the dorsal lateral geniculate nucleus (LGN) in the macaque monkey were constructed and used as a basis for comparing laminar size, shape and topographic organization. Topographical data from the electrophysiological investigation of the LGN were displayed on maps of all 6 layers. There is a significant over-representation of central vision in the LGN. Unexpectively though, the visual representation is anisotropic over portions of most LGN layers. The linear magnification factor (millimeters along the laminar surface per degree of visual field) is not equal for all directions from a given point in the visual field. The visual representations in the parvicellular and magnocellular divisions of the LGN differ both in their emphasis on central vision and in their anisotropies. To determine the degree of individual variability, laminar maps were prepared from the LGN of 7 other hemispheres. The shapes of laminar maps varied considerably between LGN from nearly circular to highly elliptical, but the surface area was relatively constant for each layer. Topographical organization, determined by mapping the optic disc representation on the LGN laminae, and by labeling from anterograde and retrograde tracer injections in striate cortex, showed significant individual variability. The visual representations in the LGN and striate cortex are topologically inverted with respect to one another; the establishment of geniculocortical connections may involve a systematic crossing-over of fibers. Results were compared with information from other studies in order to estimate ratios of cortical neurons to LGN neurons at different eccentricities. The total number of cortical neurons per LGN neuron is .apprx. 130 on average, but it extends over an .apprx. 10-fold range, from < 100 in the far periphery to .apprx. 1000 in the fovea. The estimated number of cells in layers 4A and 4C.beta. per parvicellular layer neuron is smaller, and extends over a slightly narrower range from 30-240, whereas the number of layer 4C.alpha. neurons per magnocellular neuron varies more widely from about 45-7000.