Neuroscience Institute, Georgia State University, Atlanta, GA, 30302, USA.
Instituto de Investigación Médica M Y M Ferreyra, INIMEC-CONICET-UNC, Córdoba, Argentina.
Sci Rep. 2021 Jan 27;11(1):2335. doi: 10.1038/s41598-021-81511-1.
Long-standing clinical findings report a dramatic surge of vasopressin in umbilical cord blood of the human neonate, but the neural underpinnings and function(s) of this phenomenon remain obscure. We studied neural activation in perinatal mice and rats, and found that birth triggers activation of the suprachiasmatic, supraoptic, and paraventricular nuclei of the hypothalamus. This was seen whether mice were born vaginally or via Cesarean section (C-section), and when birth timing was experimentally manipulated. Neuronal phenotyping showed that the activated neurons were predominantly vasopressinergic, and vasopressin mRNA increased fivefold in the hypothalamus during the 2-3 days before birth. Copeptin, a surrogate marker of vasopressin, was elevated 30-to 50-fold in plasma of perinatal mice, with higher levels after a vaginal than a C-section birth. We also found an acute decrease in plasma osmolality after a vaginal, but not C-section birth, suggesting that the difference in vasopressin release between birth modes is functionally meaningful. When vasopressin was administered centrally to newborns, we found an ~ 50% reduction in neuronal cell death in specific brain areas. Collectively, our results identify a conserved neuroendocrine response to birth that is sensitive to birth mode, and influences peripheral physiology and neurodevelopment.
长期以来的临床研究发现，人类新生儿脐带血中的血管升压素会急剧增加，但这种现象的神经基础和功能仍不清楚。我们研究了围产期小鼠和大鼠的神经激活情况，发现分娩会引发下丘脑的视交叉上核、视上核和室旁核的激活。无论是阴道分娩还是剖宫产（C -section），以及当分娩时间被人为干预时，都会出现这种情况。神经元表型研究表明，被激活的神经元主要是血管加压素能神经元，并且在出生前 2-3 天，下丘脑的血管加压素 mRNA 增加了五倍。加压素的替代标志物copeptin 在围产期小鼠的血浆中升高了 30-50 倍，阴道分娩后的水平高于剖宫产。我们还发现，阴道分娩后血浆渗透压会急性下降，但剖宫产不会，这表明分娩方式对血管升压素释放的差异在功能上具有重要意义。当将血管升压素注入新生儿的中枢时，我们发现特定脑区的神经元细胞死亡减少了约 50%。总的来说，我们的研究结果确定了一种对出生有反应的保守神经内分泌反应，这种反应对出生方式敏感，并影响外周生理和神经发育。
