Human Hippocampal Neurogenesis Persists Throughout the Eighth Decade of Life_Boldrini et al

Adult hippocampal neurogenesis declines in aging rodents and primates. Smaller dentate gyrus (DG), less exercise-induced angiogenesis, and waning neurogenesis, are hypothesized in aging humans. No study has assessed neurogenesis, angiogenesis and DG volume concurrently in autopsy anterior-mid-posterior hippocampus from healthy humans. We show that individuals 14 to 79 years of age have similar numbers of intermediate neural progenitors and immature neurons (thousands) in the DG neurogenic niche, have comparable numbers of glia and mature granule neurons (millions), and equivalent DG volume. Nevertheless, older individuals have less angiogenesis and neuroplasticity, and smaller quiescent progenitor pool, selectively in anterior-mid DG, with no changes in posterior DG. Preserved neurogenesis in healthy older individuals without cognitive impairment, neuropsychiatric disease or treatment, possibly sustains human-specific complex cognitive functions during a long lifespan. Diminishing angiogenesis, neuroplasticity and stem cell pool may account for declining cognitive-emotional resilience, and they might be possible targets to enhance healthy aging.

成年啮齿动物和灵长类动物的海马体神经发生随年龄增长而下降。在衰老的人类中，齿状回（DG）体积减小、运动诱导的血管生成减少以及神经发生的衰退被假设存在。迄今为止，尚无研究对健康人类尸检前中后海马体的神经发生、血管生成和DG体积进行同时评估。本研究表明，14至79岁的个体在齿状回神经发生区域具有相似数量的中间神经祖细胞和未成熟神经元（数千个），具有相当数量的胶质细胞和成熟的颗粒神经元（数百万个），以及相当的DG体积。然而，老年个体的血管生成和神经可塑性降低，静息祖细胞池减小，特别是在前中齿状回，而后齿状回则没有变化。在无认知障碍、神经精神疾病或治疗的健康老年个体中，神经发生的维持可能有助于在长寿期间维持人类特有的复杂认知功能。血管生成、神经可塑性和干细胞池的减少可能导致认知-情绪弹性的下降，它们可能成为增强健康老龄化的潜在靶点。