Chen Xiaohua, Sachdev Perminder S, Wen Wei, Anstey Kaarin J
School of Psychiatry, University of New South Wales, Australia.
Neuroimage. 2007 Jul 1;36(3):691-9. doi: 10.1016/j.neuroimage.2007.03.063. Epub 2007 Apr 12.
The study examined sex-related differences in regional gray matter (GM) in 44-48 year old healthy individuals. T1-weighted MRI scans were acquired in 411 subjects aged 44-48 from a random community sample and optimized voxel-based morphometry was applied to detect regional GM difference between men and women, correcting for effects of age, years of education, handedness, and total intracranial volume (TIV). Men had larger brain volumes and higher white matter (WM) to TIV ratios compared with women. Women had higher GM to TIV ratios than men. After controlling for age, years of education, handedness, and TIV, there were no significant differences between men and women in the total GM volumes. Regional sex dimorphism was present, with men having more GM volume in midbrain, left inferior temporal gyrus, right occipital lingual gyrus, right middle temporal gyrus, and both cerebellar hemispheres. Women showed more GM in dorsal anterior, posterior and ventral cingulate cortices, and right inferior parietal lobule. Our results suggest sex dimorphism in GM in middle aged healthy individuals, which is not likely to be explained by brain pathology. These differences may provide the structural brain basis for sex differences in certain cognitive functions.
该研究调查了44至48岁健康个体脑区灰质（GM）的性别差异。对来自随机社区样本的411名年龄在44至48岁的受试者进行了T1加权磁共振成像扫描，并应用优化的基于体素的形态测量法来检测男性和女性之间的脑区灰质差异，同时校正年龄、受教育年限、利手和总颅内体积（TIV）的影响。与女性相比，男性的脑容量更大，白质（WM）与TIV的比值更高。女性的GM与TIV的比值高于男性。在控制了年龄、受教育年限、利手和TIV后，男性和女性的总GM体积没有显著差异。存在区域性别二态性，男性在中脑、左侧颞下回、右侧枕舌回、右侧颞中回和双侧小脑半球的GM体积更多。女性在背侧前扣带回、后扣带回和腹侧扣带回皮质以及右侧顶下小叶的GM更多。我们的结果表明中年健康个体的脑区灰质存在性别二态性，这不太可能由脑部病变来解释。这些差异可能为某些认知功能的性别差异提供大脑结构基础。
