Department of Psychological and Brain Sciences, University of California, Santa Barbara, USA.
Department of Psychological and Brain Sciences, University of California, Santa Barbara, USA.
Neuroimage. 2020 Oct 15;220:117125. doi: 10.1016/j.neuroimage.2020.117125. Epub 2020 Jul 4.
The rhythmic production of sex steroid hormones is a central feature of the mammalian endocrine system. In rodents and nonhuman primates, sex hormones are powerful regulators of hippocampal subfield morphology. However, it remains unknown whether intrinsic fluctuations in sex hormones alter hippocampal morphology in the human brain. In a series of dense-sampling studies, we used high-resolution imaging of the medial temporal lobe (MTL) to determine whether endogenous fluctuations (Study 1) and exogenous manipulation (Study 2) of sex hormones alter MTL volume over time. Across the menstrual cycle, intrinsic fluctuations in progesterone were associated with volumetric changes in CA2/3, entorhinal, perirhinal, and parahippocampal cortex. Chronic progesterone suppression abolished these cycle-dependent effects and led to pronounced volumetric changes in entorhinal cortex and CA2/3 relative to freely cycling conditions. No associations with estradiol were observed. These results establish progesterone's ability to rapidly and dynamically shape MTL morphology across the human menstrual cycle.
甾体激素的节律性产生是哺乳动物内分泌系统的一个主要特征。在啮齿动物和非人类灵长类动物中，性激素是调节海马亚区形态的强大调节剂。然而，目前尚不清楚性激素的内在波动是否会改变人类大脑中的海马体形态。在一系列密集采样研究中，我们使用内侧颞叶 (MTL) 的高分辨率成像来确定内源性波动（研究 1）和外源性激素处理（研究 2）是否会随时间改变 MTL 体积。在整个月经周期中，孕激素的内在波动与 CA2/3、内嗅皮质、旁嗅皮质和海马旁皮质的体积变化有关。慢性孕激素抑制消除了这些与周期相关的影响，并导致与自由循环条件相比，内嗅皮质和 CA2/3 的体积发生明显变化。未观察到与雌二醇的关联。这些结果确立了孕激素在人类月经周期内快速而动态地塑造 MTL 形态的能力。
