Savic Ivanka, Frisen Louise, Manzouri Amirhossein, Nordenstrom Anna, Lindén Hirschberg Angelica
Department of Women's and Children's Health, Karolinska Institutet, Stockholm, SE-113 30, Sweden.
Department of Neurology, Stockholm, SE-113 30, Sweden.
Hum Brain Mapp. 2017 Apr;38(4):1801-1814. doi: 10.1002/hbm.23483. Epub 2017 Jan 10.
Women with complete androgen insensitivity syndrome (CAIS) have a male (46,XY) karyotype but no functional androgen receptors. Their condition, therefore, offers a unique model for studying testosterone effects on cerebral sex dimorphism. We present MRI data from 16 women with CAIS and 32 male (46,XY) and 32 female (46,XX) controls.
FreeSurfer software was employed to measure cortical thickness and subcortical structural volumes. Axonal connections, indexed by fractional anisotropy, (FA) were measured with diffusion tensor imaging, and functional connectivity with resting state fMRI.
Compared to men, CAIS women displayed a "female" pattern by having thicker parietal and occipital cortices, lower FA values in the right corticospinal, superior and inferior longitudinal tracts, and corpus callosum. Their functional connectivity from the amygdala to the medial prefrontal cortex, was stronger and amygdala-connections to the motor cortex weaker than in control men. CAIS and control women also showed stronger posterior cingulate and precuneus connections in the default mode network. Thickness of the motor cortex, the caudate volume, and the FA in the callosal body followed, however, a "male" pattern.
Altogether, these data suggest that testosterone modulates the microstructure of somatosensory and visual cortices and their axonal connections to the frontal cortex. Testosterone also influenced functional connections from the amygdala, whereas the motor cortex could, in agreement with our previous reports, be moderated by processes linked to X-chromosome gene dosage. These data raise the question about other genetic factors masculinizing the human brain than the SRY gene and testosterone. Hum Brain Mapp 38:1801-1814, 2017. © 2017 Wiley Periodicals, Inc.
完全性雄激素不敏感综合征（CAIS）女性具有男性（46，XY）核型，但没有功能性雄激素受体。因此，她们的情况为研究睾酮对脑性二态性的影响提供了一个独特的模型。我们展示了16名CAIS女性以及32名男性（46，XY）和32名女性（46，XX）对照的MRI数据。
使用FreeSurfer软件测量皮质厚度和皮质下结构体积。通过扩散张量成像测量以分数各向异性（FA）为指标的轴突连接，并使用静息态功能磁共振成像测量功能连接。
与男性相比，CAIS女性表现出“女性”模式，即顶叶和枕叶皮质更厚，右侧皮质脊髓束、上纵束和下纵束以及胼胝体的FA值更低。与对照男性相比，她们从杏仁核到内侧前额叶皮质的功能连接更强，而杏仁核与运动皮质的连接更弱。CAIS女性和对照女性在默认模式网络中也表现出更强的后扣带回和楔前叶连接。然而，运动皮质厚度、尾状核体积和胼胝体部的FA遵循“男性”模式。
总体而言，这些数据表明睾酮调节体感和视觉皮质的微观结构及其与额叶皮质的轴突连接。睾酮还影响来自杏仁核的功能连接，而运动皮质可能如我们之前的报告所述，受与X染色体基因剂量相关的过程调节。这些数据提出了除SRY基因和睾酮外，还有哪些其他遗传因素使人类大脑男性化的问题。《人类大脑图谱》38:1801 - 1814，2017。© 2017威利期刊公司。
