Larkman A U
University Laboratory of Physiology, Oxford University, United Kingdom.
J Comp Neurol. 1991 Apr 8;306(2):320-31. doi: 10.1002/cne.903060208.
This study concerns the correlations between the various morphometric parameters obtained for the dendrites of neocortical pyramidal cells. The primary aims were to uncover underlying design principles in dendritic morphology, to see if these differed between different types of dendrite, and to see if estimates of parameters such as total dendritic shaft membrane area could be obtained from a limited number of measurements, avoiding the need to measure every dendritic segment. The data were from a sample of 39 pyramidal neurones, from layers 2/3 and 5 of the visual cortex of the rat, that had been injected with horseradish peroxidase, reconstructed, and measured with the light microscope as part of an earlier study (Larkman and Mason, '90: J. Neurosci. 10:1407-1414). Correlations between the somal area or the combined diameters of the stem segments and measures of the overall size of the dendrites were generally weak. For basal dendrites, the size of a tree was correlated with both its number of tips and the diameter of its stem segment, but these correlations were weaker for apical dendrites. Within individual cells, the diameter of any basal segment was closely related to the size of the tree arising from it, and quantitatively similar relations applied to apical oblique trees from the same cell. Terminal arbor trees showed relations that were similar in pattern but differed quantitatively, whereas apical trunk segment diameter correlations were often weak. In all cases, the number of tips in a tree was closely related to its size. Segment lengths, however, were not closely related to the size of the trees arising from them. It appears that at least some aspects of pyramidal dendritic morphology obey simple design rules. There was heterogeneity between trees of different types, although basal and oblique trees were very similar in most respects. It should prove possible to make use of correlations to estimate the sizes of basal, oblique, and terminal arbor trees from a limited number of measurements, but this does not seem to be possible for apical trunks.
本研究关注新皮质锥体细胞树突所获得的各种形态测量参数之间的相关性。主要目的是揭示树突形态的潜在设计原则，查看这些原则在不同类型的树突之间是否存在差异，以及查看是否可以通过有限数量的测量获得诸如树突干膜总面积等参数的估计值，从而避免对每个树突段进行测量。数据来自39个锥体神经元的样本，这些神经元取自大鼠视觉皮层的第2/3层和第5层，在一项早期研究（Larkman和Mason，1990年：《神经科学杂志》10：1407 - 1414）中已注射辣根过氧化物酶、进行重建并用光学显微镜测量。胞体面积或干段的组合直径与树突整体大小的测量值之间的相关性通常较弱。对于基底树突，树的大小与其末梢数量和干段直径均相关，但对于顶树突，这些相关性较弱。在单个细胞内，任何基底段的直径与其产生的树的大小密切相关，并且相同细胞的顶斜树也存在定量相似的关系。终末分支树显示出模式相似但数量上不同的关系，而顶干段直径的相关性通常较弱。在所有情况下，树中的末梢数量与其大小密切相关。然而，段长度与由它们产生的树的大小没有密切关系。似乎锥体细胞树突形态的至少某些方面遵循简单的设计规则。不同类型的树之间存在异质性，尽管基底树和斜树在大多数方面非常相似。利用相关性从有限数量的测量中估计基底树、斜树和终末分支树的大小应该是可行的，但对于顶干似乎不太可能。
