Hayes T L, Lewis D A
Department of Behavioral Neuroscience, University of Pittsburgh, PA 15213.
Arch Neurol. 1993 May;50(5):501-5. doi: 10.1001/archneur.1993.00540050053015.
The major objective of this study was to determine if the lateralization of motor speech functions may be associated with hemispheric differences in the size of layer III pyramidal neurons in Brodmann's area 45.
A case series design involving postmortem human specimens was used to compare the cross-sectional area of NissI-stained layer III pyramidal neurons of Brodmann's area 45 from the left and right hemispheres.
A convenience sample consisting of seven cases with no known neurological or psychiatric disorders was obtained at autopsy.
The cross-sectional area of layer III pyramidal neurons in both left and right hemispheres was measured in four fields per hemisphere per brain using a computerized image analysis system. Measurements of both the largest layer III pyramids and of all layer III pyramids were done.
The largest layer III pyramidal neurons of area 45 were significantly larger in the left than in the right hemisphere in both an unblinded and a blinded series of measurements. However, this hemispheric difference appeared to be restricted to the largest neurons, since the mean size of all layer III pyramids in this area was not significantly different in the left and right hemispheres.
The presence of a unique population of large pyramidal neurons in left Brodmann's area 45 may be related to the involvement of this region in the circuitry that mediates motor speech functions.
本研究的主要目的是确定运动性言语功能的偏侧化是否可能与布罗德曼45区III层锥体神经元大小的半球差异有关。
采用涉及尸检人体标本的病例系列设计，比较左右半球布罗德曼45区经尼氏染色的III层锥体神经元的横截面积。
在尸检时获得了一个由7例无已知神经或精神疾病的病例组成的便利样本。
使用计算机图像分析系统，在每个大脑半球的四个视野中测量左右半球III层锥体神经元的横截面积。对最大的III层锥体神经元和所有III层锥体神经元都进行了测量。
在未设盲和设盲的系列测量中，45区最大的III层锥体神经元在左半球均显著大于右半球。然而，这种半球差异似乎仅限于最大的神经元，因为该区域所有III层锥体神经元的平均大小在左右半球并无显著差异。
左布罗德曼45区存在独特的大锥体神经元群，这可能与该区域参与介导运动性言语功能的神经回路有关。
