Functional roles of astrocytes in modulating neural stem and progenitor cells in the adult mammalian spinal cord

成年哺乳动物的脊髓缺乏自我修复的能力，尽管脊髓内存在组织特异性神经干细胞（NSCs）。在发育生长过程中，NSC显示出产生所有类型的脊髓细胞（包括神经元、星形胶质细胞和少突胶质细胞）并构建脊髓的能力。然而，在成年脊髓中，NSC的再生活性受到显著限制。有趣的是，我们的研究和其他研究的证据表明，成年脊髓损伤导致少突胶质细胞替代有限，这是一种在脊髓神经纤维周围产生髓鞘所需的胶质细胞类型。这些研究结果强烈表明，环境因素的存在，严格调节先天潜力的神经干细胞在成人脊髓。

Adult mammalian spinal cord lacks the ability for self repair despite the presence of tissue-specific neural stem cells (NSCs) inside the spinal cord. During the developmental growth, NSCs show the capacity to give rise to all types of spinal cord cells including neurons, astrocytes and oligodendrocytes and build the spinal cord. However, in the adult spinal cord, the regenerative activity of NSCs is significantly restricted. Interestingly, evidence from our research and that of others demonstrates that injuries to the adult spinal cord result in limited oligodendroglial cell replacement, a glial cell type required for generating myelin sheath around the spinal cord nerve fibers. These findings strongly suggest the presence of environmental factors that tightly regulate the innate potential of NSCs within the adult spinal cord.