Lei Xinjuan, Wu Yajun, Xu MengMeng, Jones Odell D, Ma Jianjie, Xu Xuehong
1National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China/CGDB, Shaanxi Normal University College of Life Sciences, Xi'an, 710119 China.
2Department of Pediatrics, Columbia University, New York, NY 10032 USA.
Cell Biosci. 2019 Sep 3;9:74. doi: 10.1186/s13578-019-0337-4. eCollection 2019.
Whether neurogenesis occurs in the adult human brain has been a long-debated topic fueled by conflicting data both for and against neurogenesis in the mature brain. Recent reports from two independent teams may have indubitably proven that adult, hippocampal neurogenesis persists throughout the human lifespan. Llorens-Martín et al. found that thousands of immature, neurogenesis related, doublecortin-positive (DCX) labelled neurons can be detected in the human dentate gyrus (DG) up to the eighth decade of life. While the presence of these DCX neurons decrease with age, they are significantly decrease in patient with Alzheimer's disease. Another group have also found mammalian embryonic Hopx precursors to persist beyond the early development stage as quiescent Hopx radial glial-like neural progenitors during early postnatal period, then as Hopx adult dentate neural progenitors. Together, the findings from these two groups suggest that unlike the previously thought, neurogenesis and neuroplasticity can occur well into adulthood in some capacity, at least in the hippocampus. These recent findings that neurogenesis can occur beyond development have brought into questions whether physical exercise can be shown to promote neurogenesis and brain health, as it has been shown to promote the function of other organ systems. Some data has already shown physical exercise to induce adult hippocampal neurogenesis (AHN) as demonstrated by restoration of cognitive functions, improvement of synaptic plasticity, and enhancement of angiogenesis. A large-scale meta-analysis has also demonstrated that 45-60 min of moderate-intensity physical exercise to dramatically improve cognitive functions in human subjects over the age of 50. Given these convergent developments in our understanding of neurogenesis and exercise induced improvement in cognitive function, we speculate that hippocampal neurogenesis can be promoted by physical exercise and discuss the current molecular evidence supporting the likely molecular pathways involved.
成人大脑中是否发生神经发生一直是一个长期争论的话题，支持和反对成熟大脑中神经发生的数据相互矛盾，引发了这场争论。两个独立团队最近的报告可能已经确凿地证明，成人海马神经发生在人类整个生命周期中持续存在。洛伦斯 - 马丁等人发现，在人类齿状回（DG）中，直至生命的第八个十年，都能检测到数千个未成熟的、与神经发生相关的、双皮质素阳性（DCX）标记的神经元。虽然这些DCX神经元的数量会随着年龄的增长而减少，但在阿尔茨海默病患者中减少得更为显著。另一组研究人员还发现，哺乳动物胚胎期的Hopx前体细胞在出生后的早期阶段会以静止的Hopx放射状胶质样神经祖细胞的形式持续存在，之后则成为Hopx成年齿状神经祖细胞。这两组研究结果共同表明，与之前的想法不同，神经发生和神经可塑性至少在海马体中，在某种程度上可以持续到成年期。这些关于神经发生可以在发育后发生的最新发现引发了一个问题，即体育锻炼是否能够促进神经发生和大脑健康，因为体育锻炼已被证明可以促进其他器官系统的功能。一些数据已经表明，体育锻炼能够诱导成人海马神经发生（AHN），认知功能的恢复、突触可塑性的改善以及血管生成的增强都证明了这一点。一项大规模的荟萃分析也表明，45 - 60分钟的中等强度体育锻炼能显著改善50岁以上人类受试者的认知功能。鉴于我们对神经发生以及运动诱导认知功能改善的理解有了这些趋同的进展，我们推测体育锻炼可以促进海马神经发生，并讨论目前支持可能涉及的分子途径的分子证据。
