The brain is an endocrine organ, sensitive to the rhythmic changes in sex hormone production that occurs in most mammalian species. In rodents and nonhuman primates, estrogen and progesterone's impact on the brain is evident across a range of spatiotemporal scales. Yet, the influence of sex hormones on the functional architecture of the human brain is largely unknown. In this dense-sampling, deep phenotyping study, we examine the extent to which endogenous fluctuations in sex hormones alter intrinsic brain networks at rest in a woman who underwent brain imaging and venipuncture for 30 consecutive days. Standardized regression analyses illustrate estrogen and progesterone's widespread associations with functional connectivity. Time-lagged analyses examined the temporal directionality of these relationships and suggest that cortical network dynamics (particularly in the Default Mode and Dorsal Attention Networks, whose hubs are densely populated with estrogen receptors) are preceded-and perhaps driven-by hormonal fluctuations. A similar pattern of associations was observed in a follow-up study one year later. Together, these results reveal the rhythmic nature in which brain networks reorganize across the human menstrual cycle. Neuroimaging studies that densely sample the individual connectome have begun to transform our understanding of the brain's functional organization. As these results indicate, taking endocrine factors into account is critical for fully understanding the intrinsic dynamics of the human brain.

中文翻译：

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人类月经周期大脑网络的功能重组

大脑是一个内分泌器官，对发生在大多数哺乳动物物种中的性激素产生的节律变化很敏感。在啮齿动物和非人类灵长类动物中，雌激素和黄体酮对大脑的影响在一系列时空尺度上都很明显。然而，性激素对人类大脑功能结构的影响在很大程度上是未知的。在这项密集采样、深度表型研究中，我们检查了连续 30 天接受脑成像和静脉穿刺的女性，性激素的内源性波动在多大程度上改变了静息时的内在大脑网络。标准化回归分析说明雌激素和孕激素与功能连接的广泛关联。时滞分析检查了这些关系的时间方向性，并表明皮质网络动态（特别是在默认模式和背侧注意力网络中，其中心密集地布满了雌激素受体）先于激素波动，并且可能由激素波动驱动。一年后的一项后续研究中观察到了类似的关联模式。总之，这些结果揭示了大脑网络在人类月经周期中重组的节律性。对个体连接组进行密集采样的神经影像研究已经开始改变我们对大脑功能组织的理解。正如这些结果表明的那样，考虑内分泌因素对于充分理解人脑的内在动态至关重要。