Department of Public Health and Community Medicine, Section of Pharmacology, University of Verona, Verona, Italy.
Curr Pharm Des. 2012;18(13):1755-83. doi: 10.2174/138161212799859611.
Presence of neural stem cells in adult mammalian brains, including human, has been clearly demonstrated by several studies. The functional significance of adult neurogenesis is slowly emerging as new data indicate the sensitivity of this event to several "every day" external stimuli such as physical activity, learning, enriched environment, aging, stress and drugs. In addition, neurogenesis appears to be instrumental for task performance involving complex cognitive functions. Despite the growing body of evidence on the functional significance of NSC and despite the bulk of data concerning the molecular and cellular properties of NSCs and their niches, several critical questions are still open. In this work we review the literature describing i) old and new sites where NSC niche have been found in the CNS; ii) the intrinsic factors regulating the NSC potential; iii) the extrinsic factors that form the niche microenvironment. Moreover, we analyse NSC niche activation in iv) physiological and v) pathological conditions. Given the not static nature of NSCs that continuously change phenotype in response to environmental clues, a unique "identity card" for NSC identification is still lacking. Moreover, the multiple location of NSC niches that increase in diseases, leaves open the question of whether and how these structures communicate throughout long distance. We propose a model where all the NSC niches in the CNS may be connected in a functional network using the threads of the meningeal net as tracks.
成年哺乳动物大脑中存在神经干细胞，包括人类，这已被多项研究清楚地证明。随着新数据表明这种事件对多种“日常”外部刺激（如身体活动、学习、丰富的环境、衰老、压力和药物）的敏感性，成人神经发生的功能意义正在慢慢显现。此外，神经发生似乎对涉及复杂认知功能的任务表现至关重要。尽管越来越多的证据表明 NSC 的功能意义，尽管有大量的数据涉及 NSCs 及其生态位的分子和细胞特性，但仍有几个关键问题尚未解决。在这项工作中，我们回顾了描述 i）在中枢神经系统中发现 NSC 生态位的新旧部位的文献；ii）调节 NSC 潜力的内在因素；iii）形成生态位微环境的外在因素。此外，我们分析了 iv）生理和 v）病理条件下 NSC 生态位的激活。鉴于 NSCs 的非静态性质，它们会根据环境线索不断改变表型，因此仍然缺乏 NSC 鉴定的独特“身份证”。此外，在疾病中增加的 NSC 生态位的多个位置，使得这些结构是否以及如何在远距离进行通信的问题仍然存在。我们提出了一个模型，即中枢神经系统中的所有 NSC 生态位都可以使用脑膜网的线作为轨道连接成一个功能网络。
