BRANCHING AND LAMINAR ORIGIN OF PROJECTIONS BETWEEN VISUAL CORTICAL AREAS IN THE CAT
BRANCHING AND LAMINAR ORIGIN OF PROJECTIONS BETWEEN VISUAL CORTICAL AREAS IN THE CAT
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DOI：
10.1002/cne.902280304
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发表时间：
1984-01-01
影响因子：
2.5
通讯作者：
SALINGER, W
中科院分区：
文献类型：
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作者：
BULLIER, J;KENNEDY, H;SALINGER, W
通过在成年猫新皮层的17、18、19、20、21区和外侧上裂区成对注射荧光逆行标记物坚牢蓝和二脒基黄后，检查这些区域中单标记神经元的层状位置和双标记细胞的比例，研究了皮层神经元的层状分布和分支模式。18和19的同侧半球。注射18区和19区后，17区的标记神经元主要局限于颗粒上层，在第5层和第6层上层也有少量标记细胞。双标记的神经元是罕见的，被发现在该区域的重叠之间的2个群体的标记细胞。它们主要分布在上层，但在第5层和第6层也有少量。投射到这两个区域的细胞通常以斑块的形式分组，根据检查的区域，这些斑块重叠或交错。作为一个群体，投射到18区的神经元在第2层和第3层的位置比投射到19区的神经元更深。在区域17和19注射后，区域18中的标记细胞大多数位于上板层，少数双标记细胞仅限于2个标记细胞群之间的重叠区域。区域17和18注射后，区域19中的标记模式与区域17和18中观察到的标记模式不同。神经元几乎均匀分布在颗粒层和颗粒下层之间，并且有相当大比例的双标记神经元（10%）倾向于主要属于第5层和上第6层。在区域PMLS中，皮质皮质细胞的层状位置有点类似于在区域19中观察到的位置，因为在深层中发现了大量的标记神经元，特别是在17或18中注射后。在19区注射后，标记细胞主要见于上层。当注射在区域17和18时，双标记细胞很多（20%），但在其他情况下（17-19和18-19）非常罕见。双标神经元主要分布在深层。在区域17、18和19中注射后，在区域20中发现标记细胞，证明了从区域20到区域17和18的迄今未知的投影。标记细胞在20区几乎完全局限于颗粒下层。当区域17-18和18-19被注射时，双标记神经元很多（10-20%），但当区域17和19接受注射时，双标记神经元非常罕见。结果进行了讨论，在不同层次的信息处理的视觉皮层。在感觉信息加工过程中，区域17和18占据相似的水平，区域19和PMLS处于更高的水平，而区域20占据更高的水平。低水平的皮质-皮质联系往往来自颗粒上层，而从高水平到低水平的反馈主要通过颗粒下层完成。有人提出，相反的皮质下传入的分支丰富支配所有3个视觉区域，皮质皮质的预测一般不好分叉的情况下，除了在反馈的区域都占据了类似的信息处理水平。
The laminar distribution and branching pattern of corticocortical neurons were studied in areas 17, 18, 19, 20, 21, and the lateral suprasylvian areas of the adult cat neocortex, by examining the laminar position of single-labeled neurons and the proportions of double-labeled cells in these areas after paired injections of the fluorescent retrograde labels fast blue and diamidino yellow in areas 17, 18 and 19 of the ipsilateral hemisphere. After injections in areas 18 and 19, the labeled neurons in area 17 were mostly confined to the supragranular layers, with a small proportion of labeled cells in lamina 5 and upper lamina 6. Double-labeled neurons were rare and were found in the region of overlap between the 2 populations of labeled cells. They were mostly found in the upper laminae but a few were observed in laminae 5 and 6. The cells projecting to either area were often grouped in patches which were seen to overlap or interdigitate depending on the region examined. As a population, the neurons projecting to area 18 occupied a deeper position in laminae 2 and 3 than those projecting to area 19. Labeled cells in area 18 after injections in areas 17 and 19 were mostly found in the upper laminae with a few double-labeled cells which were restricted to the region of overlap between the 2 populations of labeled cells. The pattern of labeling in area 19 after injections in areas 17 and 18 was different from the one seen in areas 17 and 18. Neurons were almost equally distributed between the supra- and infragranular layers and there was a substantial proportion of double-labeled neurons (10%) which tended to belong mostly to lamina 5 and upper lamina 6. In area PMLS, the laminar position of corticocortical cells was somewhat similar to the one observed in area 19, in that a substantial number of labeled neurons were found in the deep laminae, especially after injections in 17 or 18. After injections in area 19, labeled cells were mostly found in the upper layers. Double-labeled cells were numerous (20%) when the injections were placed in areas 17 and 18 but quite rare in the other cases (17-19 and 18-19). Most of the double-labeled neurons were found in the deep layers. After injections in areas 17, 18 and 19, labeled cells were found in area 20, demonstrating a hitherto unknown projection from area 20 to areas 17 and 18. Labeled cells in area 20 were almost exclusively confined to the infragranular layers. Double-labeled neurons were numerous (10-20%) when areas 17-18 and 18-19 were injected but quite rare when areas 17 and 19 received the injections. The results are discussed in terms of different levels of processing of information in the visual cortex. It is argued that areas 17 and 18 occupy a similar level and that areas 19 and PMLS are at higher levels while area 20 occupies a still higher level in the course of sensory information processing. Corticocortical connections from low levels tend to arise from supragranular layers whereas the feedback from higher to lower levels in mostly done via infragranular laminae. It is proposed that, contrary to the subcortical afferents which branch profusely to innervate all 3 visual areas, the corticocortical projections are generally poorly bifurcated except in the case of feedback to areas both occupying a similar level in the information processing.