Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA.
Mol Psychiatry. 2022 Jan;27(1):377-382. doi: 10.1038/s41380-021-01314-8. Epub 2021 Oct 19.
In sub-mammalian vertebrates like fishes, amphibians, and reptiles, new neurons are produced during the entire lifespan. This capacity diminishes considerably in birds and even more in mammals where it persists only in the olfactory system and hippocampal dentate gyrus. Adult neurogenesis declines even more drastically in nonhuman primates and recent evidence shows that this is basically extinct in humans. Why should such seemingly useful capacity diminish during primate evolution? It has been proposed that this occurs because of the need to retain acquired complex knowledge in stable populations of neurons and their synaptic connections during many decades of human life. In this review, we will assess critically the claim of significant adult neurogenesis in humans and show how current evidence strongly indicates that humans lack this trait. In addition, we will discuss the allegation of many rodent studies that adult neurogenesis is involved in psychiatric diseases and that it is a potential mechanism for human neuron replacement and regeneration. We argue that these reports, which usually neglect significant structural and functional species-specific differences, mislead the general population into believing that there might be a cure for a variety of neuropsychiatric diseases as well as stroke and brain trauma by genesis of new neurons and their incorporation into existing synaptic circuitry.
在像鱼类、两栖动物和爬行动物这样的低等脊椎动物中，新神经元在整个生命过程中都会产生。这种能力在鸟类中会显著降低，而在哺乳动物中，这种能力仅存在于嗅觉系统和海马齿状回中。成年神经发生在非人类灵长类动物中甚至更为急剧地下降，最近的证据表明，在人类中这种能力基本已经消失。为什么这种看似有用的能力在灵长类动物进化过程中会减少呢？有人提出，这是因为需要在人类生命的几十年中，在神经元及其突触连接的稳定群体中保留获得的复杂知识。在这篇综述中，我们将批判性地评估人类存在大量成年神经发生的说法，并展示当前的证据如何强烈表明人类缺乏这种特征。此外，我们还将讨论许多啮齿动物研究的说法，即成年神经发生与精神疾病有关，并且它是人类神经元替代和再生的潜在机制。我们认为，这些报告通常忽略了物种特异性的显著结构和功能差异，使大众错误地认为通过新神经元的产生及其整合到现有的突触回路中，可能为各种神经精神疾病以及中风和脑外伤提供治疗方法。
