Sex differences in cortical thickness mapped in 176 healthy individuals between 7 and 87 years of age
Sex differences in cortical thickness mapped in 176 healthy individuals between 7 and 87 years of age
复制标题
DOI：
10.1093/cercor/bhl066
复制
发表时间：
2007-07-01
期刊：
影响因子：
3.7
通讯作者：
Toga, Arthur W.
中科院分区：
文献类型：
--
作者：
Sowell, Elizabeth R.;Peterson, Bradley S.;Toga, Arthur W.
之前关于灰质性别差异的磁共振成像研究结果并不一致，有些显示女性灰质按比例增加，有些则显示性别之间没有差异。在从幼儿期到老年的大量受试者样本中，灰质厚度的区域性别差异尚未在整个皮质表面上绘制出来。我们将皮质模式匹配算法和测量皮质厚度的技术应用于 176 名年龄在 7 岁至 87 岁之间的健康个体的结构磁共振图像。我们还绘制了大脑大小的局部差异。皮质厚度的性别差异图显示，即使没有校正总脑体积，女性右下顶叶和后颞区的皮质也更厚。在这些区域，女性的皮质套平均比男性厚 0.45 毫米。对年龄和脑容量匹配的 18 名女性和 18 名男性受试者的子集进行的分析证实了女性颞叶和顶叶皮质中较厚灰质的重要性，与大脑大小差异无关。对成年受试者进行了进一步的分析，其中使用身高作为协变量来评估性别差异，即使控制了性别之间的体型差异，也观察到类似的性别差异。总之，这些结果表明，相对于男性，女性后颞下顶叶区域的皮质厚度更大，与大脑或身体尺寸的差异无关。颞顶区的年龄与性别相互作用并不显着，这表明这些区域的性别差异至少从童年晚期就存在，然后在一生中持续存在。男性大脑在所有部位都比女性大脑大，但男性大脑两侧的额叶和枕极增大最为明显。鉴于研究样本量大、年龄范围大，这些结果有助于解决中枢神经系统性别二态性研究中的争议。
Findings from previous magnetic resonance imaging studies of sex differences in gray matter have been inconsistent, with some showing proportionally increased gray matter in women and some showing no differences between the sexes. Regional sex differences in gray matter thickness have not yet been mapped over the ntire cortical surface in a large sample of subjects spanning the age range from early childhood to old age. We applied algorithms for cortical pattern matching and techniques for measuring cortical thickness to the structural magnetic resonance images of 176 healthy individuals between the ages of 7 and 87 years. We also mapped localized differences in brain size. Maps of sex differences in cortical thickness revealed thicker cortices in women in right inferior parietal and posterior temporal regions even without correcting for total brain volume. In these regions, the cortical mantle is up to 0.45 mm thicker, on average, in women than in men. Analysis of a subset of 18 female and 18 male subjects matched for age and brain volume confirmed the significance of thicker gray matter in temporal and parietal cortices in females' independent of brain size differences. Further analyses were conducted in the adult subjects where gender differences were evaluated using height as a covariate, and similar sex differences were observed even when body size differences between the sexes were controlled. Together, these results suggest that greater cortical thickness in posterior temporal inferior parietal regions in females relative to males are independent of differences in brain or body size. Age-by-sex interactions were not significant in the temporoparietal region, suggesting that sex differences in these regions are present from at least late childhood and then are maintained throughout life. Male brains were larger than female brains in all locations, though male enlargement was most prominent in the frontal and occipital poles, bilaterally. Given the large sample and the large range of ages studied, these results help to address controversies in the study of central nervous system sexual dimorphisms.