Reid S N, Juraska J M
Neuroscience Program, University of Illinois, Champaign-Urbana 61820.
J Comp Neurol. 1992 Jul 15;321(3):448-55. doi: 10.1002/cne.903210311.
We have previously shown that the thickness of the binocular area of the primary visual cortex is sexually dimorphic in rats. In the present study, sex differences in the number of neurons in this cortical area were examined in nine littermate pairs of 90-day-old Long-Evans hooded rats. Cytoarchitectonic characteristics were used to define the binocular visual cortex, and its volume was estimated through three-dimensional reconstruction of serial coronal sections for each hemisphere. Neuronal and glial density as well as neuronal soma size were estimated from semithin sections through a stereological technique, the disector, in the same animals that were used to estimate volume. The volume of the binocular area was 19% greater in males than in females. While there were no sex differences in soma size or in neuronal density, the differences in the volume of the binocular area resulted in significant sex differences (male greater than female) in the number of neurons overall and in every layer, except layer IV. Glial density was not different between the sexes, but the total number of glial cells was higher in males than in females. These results demonstrate that the binocular visual cortex of the rat is sexually dimorphic in its volume and much of the difference is due to sex differences in the number of neurons and glial cells.
我们之前已经表明，大鼠初级视觉皮层双眼区的厚度存在性别差异。在本研究中，我们对9对同窝出生的90日龄长-伊 Evans 戴帽大鼠的该皮层区域神经元数量的性别差异进行了检测。利用细胞构筑特征来定义双眼视觉皮层，并通过对每个半球的连续冠状切片进行三维重建来估计其体积。在用于估计体积的同一批动物中，通过体视学技术（即分割法）从半薄切片中估计神经元和胶质细胞密度以及神经元胞体大小。雄性大鼠双眼区的体积比雌性大鼠大19%。虽然在胞体大小或神经元密度方面没有性别差异，但双眼区体积的差异导致除IV层外，各层以及总体神经元数量存在显著的性别差异（雄性多于雌性）。两性之间的胶质细胞密度没有差异，但雄性大鼠的胶质细胞总数高于雌性大鼠。这些结果表明，大鼠的双眼视觉皮层在体积上存在性别差异，且大部分差异是由于神经元和胶质细胞数量的性别差异所致。
