Kalcheim C, Le Douarin N M
Dev Biol. 1986 Aug;116(2):451-66. doi: 10.1016/0012-1606(86)90146-6.
The influence of the neural tube on early development of neural crest cells into sensory ganglia was studied in the chick embryo. Silastic membranes were implanted between the neural tube and the somites in 30-somite-stage embryos at the level of somites 21-24, thus separating the early migrated population of neural crest cells from the neural tube. Neural crest cells and peripheral ganglia were visualized by immunofluorescence using the HNK-1 monoclonal antibody and several histochemical techniques. Separation of crest cells from the neural tube caused the selective death of the neural crest cells from which dorsal root ganglia (DRG) would have developed. Complete disappearance of HNK-1 positive cells was evident already 10 hr after silastic implantation, before early differentiation sensory neurons could have reached their peripheral targets. In older embryos, DRG were absent at the level of implantation. In contrast, the development of ventral roots, sympathetic ganglia and adrenal gland was normal, and so was somitic differentiation into cartilage and muscle, while morphogenesis of the vertebrae was perturbed. To overcome the experimentally induced crest cell death, the silastic membranes were impregnated with a 3-day-old embryonic chick neural tube extract. Under these conditions, crest cells which were separated from the tube survived for a period of 30 hr after operation, compared to less than 10 hr in respective controls. The extract of another tissue, the liver, did not protract survival of DRG progenitor cells. Among the cells which survived with neural tube extract, some even succeeded in extending neurites; nevertheless, in absence of normal connections with the central nervous system (CNS) they finally died. Treatment of silastic implanted embryos with nerve growth factor (NGF) did not prevent the experimentally induced crest cell death. These results demonstrate that DRG develop from a population of neural crest cells which depends for its survival and probably for its differentiation upon a signal arising from the CNS, needed as early as the first hours after initiation of migration. Recovery experiments suggest that the subpopulation of crest cells which will develop along the sensory pathway probably depends for its survival and/or differentiation upon a factor contained in the neural tube, which is different from NGF.
在鸡胚中研究了神经管对神经嵴细胞早期发育成感觉神经节的影响。在21 - 24体节水平的30体节期胚胎的神经管和体节之间植入硅橡胶膜，从而将早期迁移的神经嵴细胞群体与神经管分离。使用HNK - 1单克隆抗体和几种组织化学技术通过免疫荧光观察神经嵴细胞和外周神经节。将嵴细胞与神经管分离导致了本应发育为背根神经节（DRG）的神经嵴细胞选择性死亡。在硅橡胶植入后10小时，早在早期分化的感觉神经元到达其外周靶点之前，HNK - 1阳性细胞就已明显完全消失。在较老的胚胎中，植入水平处没有DRG。相比之下，腹根、交感神经节和肾上腺的发育正常，体节分化为软骨和肌肉也正常，而椎骨的形态发生受到干扰。为了克服实验诱导的嵴细胞死亡，将硅橡胶膜用3日龄鸡胚神经管提取物浸渍。在这些条件下，与各自对照组中不到10小时相比，从神经管分离的嵴细胞在手术后存活了30小时。另一种组织肝脏的提取物并没有延长DRG祖细胞的存活时间。在使用神经管提取物存活的细胞中，一些甚至成功地长出了神经突；然而，由于与中枢神经系统（CNS）没有正常连接，它们最终死亡。用神经生长因子（NGF）处理植入硅橡胶的胚胎并不能防止实验诱导的嵴细胞死亡。这些结果表明，DRG由一群神经嵴细胞发育而来，这群细胞的存活以及可能的分化依赖于中枢神经系统产生的一种信号，这种信号在迁移开始后的最初几个小时就需要。恢复实验表明，将沿着感觉通路发育的嵴细胞亚群的存活和/或分化可能依赖于神经管中含有的一种不同于NGF的因子。
