DENDRITIC MORPHOLOGY OF PYRAMIDAL NEURONS OF THE VISUAL-CORTEX OF THE RAT .3. SPINE DISTRIBUTIONS
DENDRITIC MORPHOLOGY OF PYRAMIDAL NEURONS OF THE VISUAL-CORTEX OF THE RAT .3. SPINE DISTRIBUTIONS
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DOI：
10.1002/cne.903060209
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发表时间：
1991-04-08
影响因子：
2.5
通讯作者：
LARKMAN, AU
中科院分区：
文献类型：
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作者：
LARKMAN, AU
绝大多数的兴奋性突触输入到新皮质锥体细胞终止于树突棘，因此可以作为标记，通过光学显微镜可见，这些突触的位置。 本研究的目的是提供估计的总数量和分布的个别锥体神经元的树突从层2/3和5的大鼠的视觉皮层。 高放大倍数的相机清晰度图纸的树突段位于接近截面的平面和数量的棘每单位长度的树突计算。 这些棘密度用于估计其他树突节段上的棘数量，并将结果输入计算各种统计数据的计算机程序。对于第2/3层细胞，对于细长的第5层细胞为8，647 +/-3，097，对于厚的第5层细胞为14，932 +/-3，371;这些数字与先前的体视学估计非常一致。 对于所有的细胞类别，70%或更多的棘位于基底和顶端斜树突。 棘相对于皮质层的分布也进行了探讨。 大多数细胞的大部分棘在含有索马的层中，但在细胞类内和细胞类之间存在差异。 第2/3层细胞随着其索马体在皮层中深度的增加，其在第1和第2层中的棘的比例逐渐减少。 厚层5细胞具有来自层4、3、2的实质性贡献，并且特别是层1。 细长的第5层细胞对第6层和第4层细胞的贡献较小，而第3层和第2层细胞的棘相对较少。通过估计以索马为中心的一系列同心壳中所含棘的数量，探索了棘与到索马的路径距离的分布。 所有的细胞表现出快速增加的刺每壳的数量为近端100 μ m左右，然后急剧下降到约250 μ m，超过此数量保持相对恒定，直到终端乔木结束。 在每种情况下，大多数的棘位于从索马的路径长度为150 μ m。
The vast majority of excitatory synaptic inputs to neocortical pyramidal cells terminate on dendritic spines, which can thus serve as markers, visible by light microscopy, for the locations of these synapses. The aim of this study was to provide estimates of the total numbers and distributions of spines on the dendrites of individual pyramidal neurones from layers 2/3 and 5 of the visual cortex of the rat. High magnification camera lucida drawings were made of dendritic segments lying close to the plane of section and the number of spines per unit length of dendrite calculated for each. These spine densities were used to estimate the numbers of spines on the other dendritic segments and the results were entered to a computer program that calculated various statistics.Mean total numbers of spines per cell were 7,965 +/- 2,723 (S.D.) for layer 2/3 cells, 8,647 +/- 3,097 for slender layer 5 cells, and 14,932 +/- 3,371 for thick layer 5 cells; these figures are in good agreement with previous stereological estimates. For all cell classes, 70% or more of spines were located on the basal and apical oblique dendrites. The distribution of spines with respect to cortical layers was also explored. Most cells had most of their spines in the layer containing the soma, but there were differences within and between cell classes. Layer 2/3 cells showed a progressive reduction in the proportion of their spines in layers 1 and 2 with increasing depth of their soma in the cortex. Thick layer 5 cells had substantial contributions from layers 4, 3, 2, and especially layer 1. Slender layer 5 cells had small contributions from layers 6 and 4, but relatively few spines in layers 3 and 2.The distribution of spines with path distance from the soma was explored by estimating the numbers of spines contained within a series of concentric shells centred on the soma. All cells showed a rapid increase in the number of spines per shell for the proximal 100-mu-m or so, followed by a sharp decline to approximately 250-mu-m, beyond which the number remained relatively constant until the end of the terminal arbor. In each case, the majority of spines were located within a path length of 150-mu-m from the soma.