Animal studies have shown that pregnancy is associated with neural adaptations that promote maternal care. The hypothalamus represents a central structure of the mammalian maternal brain and hormonal priming of specific hypothalamic nuclei plays a key role in the induction and expression of maternal behavior. In humans, we have previously demonstrated that becoming a mother involves changes in grey matter anatomy, primarily in association areas of the cerebral cortex. In the current study, we investigated whether pregnancy renders anatomical changes in the hypothalamus. Using an advanced delineation technique, five hypothalamic substructures were defined in longitudinal MRI scans of 107 women extracted from two prospective pre-conception cohort studies, including 50 women who were scanned before and after pregnancy and 57 nulliparous control women scanned at a similar time interval. We showed that becoming a mother is associated with volume reductions in the anterior-superior, superior tuberal and posterior hypothalamus. In addition, these structural changes related to hormonal levels during pregnancy and specific aspects of self-reported maternal behavior in late pregnancy, including maternal-fetal attachment and nesting behavior. These findings show that pregnancy leads to changes in hypothalamic anatomy and suggest that these contribute to the development of maternal behavior in humans, supporting the conservation of key aspects of maternal brain circuitry and their role in maternal behavior across species.

中文翻译：

---

怀孕会导致人脑下丘脑亚结构发生解剖学变化，这些变化与母亲行为的各个方面有关

动物研究表明，怀孕与促进孕产妇护理的神经适应有关。下丘脑代表哺乳动物母体大脑的中心结构，特定下丘脑核的激素启动在母体行为的诱导和表达中起着关键作用。在人类中，我们之前已经证明，成为母亲涉及灰质解剖结构的变化，主要是大脑皮层关联区域的变化。在当前的研究中，我们研究了怀孕是否会导致下丘脑的解剖学变化。使用先进的描绘技术，对从两项前瞻性孕前队列研究中提取的 107 名女性进行纵向 MRI 扫描，确定了 5 个下丘脑亚结构，其中包括 50 名在怀孕前后接受扫描的女性和 57 名在相似时间间隔进行扫描的未产妇对照女性。我们发现，成为母亲与下丘脑前上、上结节和后部体积减少有关。此外，这些结构变化与怀孕期间的荷尔蒙水平以及怀孕后期自我报告的母亲行为的具体方面有关，包括母婴依恋和筑巢行为。这些发现表明，怀孕会导致下丘脑解剖结构的变化，并表明这些变化有助于人类母性行为的发展，支持母性大脑回路关键部分的保护及其在跨物种母性行为中的作用。