Why sex matters: brain size independent differences in gray matter distributions between men and women.
Why sex matters: brain size independent differences in gray matter distributions between men and women.
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DOI：
10.1523/jneurosci.2261-09.2009
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发表时间：
2009-11-11
期刊：
影响因子：
--
通讯作者：
Toga AW
中科院分区：
文献类型：
--
作者：
Luders E;Gaser C;Narr KL;Toga AW
男性和女性大脑解剖结构的不同是一个经典的和持续的主要兴趣话题。其中最具复制性和鲁棒性的性别差异是男性的整体大脑尺寸更大，女性的整体和区域灰质（GM）相对增加。然而，问题仍然是大脑大小的性别典型差异（即，男性大脑较大，女性大脑较小）或生物性别本身解释了观察到的对组织数量和分布的性别效应。探索大脑大小相似的男性和女性的大脑结构可能会澄清生物性别的真正贡献。因此，我们研究了一个样本的24名男性和24名女性的大脑大小相同，除了24名男性和24名女性的大脑大小有相当大的差异。使用这一大组大脑（n=96），我们应用了一种经过充分验证和自动化的基于体素的方法来检查GM的区域体积。虽然我们揭示了性别的显著主要影响，但大脑大小没有显著影响（性别和大脑大小之间没有显著的相互作用）。在进行事后测试时，我们发现了一些女性比男性拥有更大转基因量的地区。重要的是，当比较大脑大小相同的男性和女性时，这些性别影响仍然很明显。总而言之，我们的研究结果表明，所观察到的女性大脑中区域GM体积的增加构成了组织体积的性别依赖性再分布，而不是归因于大脑大小的个体调整。
The different brain anatomy of men and women is both a classic and continuing topic of major interest. Among the most replicated and robust sex differences are larger overall brain dimensions in men, and relative increases of global and regional gray matter (GM) in women. However, the question remains whether sex-typical differences in brain size (i.e., larger male and smaller female brains) or biological sex itself account for the observed sex effects on tissue amount and distribution. Exploring cerebral structures in men and women with similar brain size may clarify the true contribution of biological sex. We thus examined a sample of 24 male and 24 female subjects with brains identical in size, in addition to 24 male and 24 female subjects with considerable brain size differences. Using this large set of brains (n=96), we applied a well-validated and automated voxel-based approach to examine regional volumes of GM. While we revealed significant main effects of sex, there were no significant effects of brain size (and no significant interactions between sex and brain size). When conducting post hoc tests, we revealed a number of regions where women had larger GM volumes compared to men. Importantly, these sex effects remained evident when comparing men and women with the same brain size. Altogether, our findings suggest that the observed increased regional GM volumes in female brains constitute sex-dependent redistributions of tissue volume, rather than individual adjustments attributable to brain size.