Allen L S, Gorski R A
Department of Anatomy and Cell Biology, University of California, Los Angeles 90024.
J Comp Neurol. 1991 Oct 1;312(1):97-104. doi: 10.1002/cne.903120108.
Neuroanatomical sex differences were observed in the midsagittal area of both the anterior commissure and the massa intermedia on analysis of postmortem tissue from 100 age-matched male and female individuals. The anterior commissure, a fiber tract whose axons in primates primarily connect the two temporal lobes, was an average of 12%, or 1.17 mm2 larger in females than in males. The massa intermedia, a structure that crosses the third ventricle between the two thalami, was present in 78% of the females and 68% of the males. Among subjects with a massa intermedia, the structure was an average of 53.3% or 17.5 mm2 larger in females than in males. Inclusive of subjects with and without a massa intermedia, this structure was a mean of 76% or 16.93 mm2 greater in females than in males. These sex differences were present despite the fact that the brains of males were larger than those of females. Since a majority of subjects were adults, it is unknown when sexual differentiation occurred. Anatomical sex differences in structures that connect the two cerebral hemispheres may, in part, underlie functional sex differences in cognitive function and cerebral lateralization.
对100名年龄匹配的男性和女性个体的尸检组织进行分析后发现，在前连合和中间块的矢状中区域存在神经解剖学上的性别差异。前连合是一种纤维束，在灵长类动物中，其轴突主要连接两个颞叶，女性的前连合平均比男性大12%，即1.17平方毫米。中间块是一种在两个丘脑之间穿过第三脑室的结构，78%的女性和68%的男性存在该结构。在有中间块的受试者中，女性的该结构平均比男性大53.3%，即17.5平方毫米。包括有和没有中间块的受试者在内，女性的该结构平均比男性大76%，即16.93平方毫米。尽管男性的大脑比女性的大，但这些性别差异仍然存在。由于大多数受试者是成年人，尚不清楚性别分化何时发生。连接两个大脑半球的结构中的解剖学性别差异可能部分是认知功能和大脑侧化功能性别差异的基础。
