Hayes T L, Lewis D A
Department of Neuroscience, University of Pittsburgh, Pa, USA.
Arch Neurol. 1996 Dec;53(12):1277-83. doi: 10.1001/archneur.1996.00550120089021.
To test the hypothesis that the larger somal size of layer III magnopyramidal neurons in left than in right Brodmann area 45 is associated with greater measures of dendritic arborization in the left hemisphere neurons.
A case series involving postmortem human brain specimens was used to compare dendritic parameters of Golgi-impregnated layer III pyramidal neurons in Brodmann area 45 in the left and right hemispheres.
A convenience sample consisting of 9 subjects with no known neurologic or psychiatric disorders was obtained at autopsy.
Dendritic parameters of the 10 largest Golgi-impregnated layer III pyramidal neurons were measured in each hemisphere of each brain using a eutectic neuron tracing system. The measures examined were somal size, neuron depth, mean segment length, number of branch points, maximal branch order, combined dendritic diameter, total dendritic length, horizontal extent of the dendritic field, and spine density. The Golgi-impregnated slides were also compared with Nissl-stained slides from adjacent blocks to determine the laminar location of the sampled neurons.
Although the mean somal size was greater in the left than in the right hemisphere, none of the dendritic parameters examined was larger for the left hemisphere neurons. As expected, total dendritic length was positively correlated to somal size (r = 0.43, P < 001) in the left hemisphere. However, there was no correlation between these parameters in the right hemisphere (r = 0.02, P = .76).
The difference between left and right Brodmann area 45 magnopyramidal neurons in the correlation of somal size and dendritic length provides additional evidence of anatomical differences between these 2 populations of neurons. However, the lack of interhemispheric differences in measures of dendritic arborization suggests that additional factors contribute significantly to the marked difference in somal size between the large magnopyramidal neurons in the left and right hemispheres.
验证以下假设，即左侧布罗德曼45区第三层大锥体神经元的胞体尺寸大于右侧，这与左侧半球神经元更大程度的树突分支相关。
采用一个涉及死后人类脑标本的病例系列，比较左侧和右侧半球布罗德曼45区经高尔基染色的第三层锥体神经元的树突参数。
在尸检时获得了一个便利样本，由9名无已知神经或精神疾病的受试者组成。
使用共晶神经元追踪系统，在每个大脑的每个半球中测量10个最大的经高尔基染色的第三层锥体神经元的树突参数。所检测的指标包括胞体尺寸、神经元深度、平均节段长度、分支点数、最大分支阶数、合并树突直径、总树突长度、树突野的水平范围和棘密度。还将经高尔基染色的玻片与相邻切片的尼氏染色玻片进行比较，以确定所采样神经元的层位位置。
虽然左侧半球的平均胞体尺寸大于右侧，但所检测的树突参数在左侧半球神经元中均未更大。正如预期的那样，左侧半球中总树突长度与胞体尺寸呈正相关（r = 0.43，P < 0.01）。然而，右侧半球中这些参数之间无相关性（r = 0.02，P = 0.76）。
左侧和右侧布罗德曼45区大锥体神经元在胞体尺寸与树突长度相关性上的差异，为这两类神经元之间的解剖学差异提供了额外证据。然而，树突分支测量中缺乏半球间差异表明，其他因素对左右半球大锥体神经元胞体尺寸的显著差异有重大影响。
