Various types of corticotectal neurons of cats as demonstrated by means of retrograde axonal transport of horseradish peroxidase
Various types of corticotectal neurons of cats as demonstrated by means of retrograde axonal transport of horseradish peroxidase
复制标题
通过辣根过氧化物酶的逆行轴突运输证明猫的各种类型的皮质顶盖神经元
作者：
K. Kawamura;T. Konno
摘要 采用辣根过氧化物酶（HRP）逆行标记皮层神经元，研究了猫投射到上丘的各个皮层区域神经元的形态特征。发现皮层细胞被标记在整个大脑皮层的V层。标记细胞的数量及其位置根据丘中 HRP 的注射部位而变化。本研究中发现的大多数皮质顶盖细胞都是小型（直径 9-20 μm，66%）和中等（20-40 um，30%）锥体神经元，只有 4% 是大型（超过 40 μm）。标记细胞总数为261个，细胞直径为20.8±8.0μm（平均值和标准差）。不同皮质区域标记神经元的大小范围不同。例如，克莱尔-毕夏普区域的标记神经元比其他区域具有更大比例的大直径细胞。就皮质顶盖投影的地形相关性而言，目前的发现与之前的顺行变性方法的数据基本一致。然而，在一些皮质区域，例如半球外侧表面的感觉运动皮质和第一视觉皮质（区域 17），相对少量的皮质顶盖神经元似乎被逆行转运的 HRP 标记。某些皮质区域中标记神经元的稀疏性可能反映了皮质顶盖神经元的存在，其轴突侧支为上丘以外的大脑结构提供供应。
SummaryThe retrograde labeling of cortical neurons with horseradish peroxidase (HRP) was used to investigate the morphological features of neurons in various cortical areas projecting to the superior colliculus in the cat.Corticotectal cells were found to be labeled in layer V of the entire cerebral cortex. The number of labeled cells and their locations varied according to the sites of injections of HRP in the colliculus. Most of the Corticotectal cells identified in the present study were small (9–20 μm in diameter, 66%) and medium (20–40 urn, 30%) pyramidal neurons and only 4% of them were large (more than 40 μm). The labeled cells, 261 in total number, had somal diameters of 20.8±8.0 μm (mean and SD). The range of sizes of the labeled neurons was different in different cortical areas. For example, the labeled neurons in the Clare-Bishop area had a greater proportion of large diameter cells than in other areas.The present findings are largely in agreement with the previous data of anterograde degeneration methods with respect to the topographical correlation of the Corticotectal projections. However, in some cortical areas, e.g., the sensorimotor and the first visual (area 17) cortex of the lateral surface of the hemisphere, relatively small numbers of Corticotectal neurons appear to have been labeled by retrogradely transported HRP. The sparsity of the labeled neurons in certain cortical areas may reflect the existence of Corticotectal neurons with axon collaterals supplying brain structures other than the superior colliculus.