期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1972
卷号:69
期号:7
页码:1962-1966
DOI:10.1073/pnas.69.7.1962
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Neurogenesis was studied in rat spinal cord by correlation of the observations from [3H]thymidine autoradiography and Golgi techniques. The temporal pattern of the origin of neurons systematically lagged along the ventro-dorsal and rostro-caudal axes. The temporal pattern was correlated with the topographic pattern of the release and segregation of the newly formed neuroblasts from the neuroepithelium. These temporal and topographic patterns of neuroblast genesis imparted an order to the settling of the neuroblasts. Further, the emerging cytoarchitecture of the differentiating neuroblasts resulted in the formation of oriented interfaces along which the axons grew. The "pioneering" fibers grew along the interfaces formed by the regressed neuroepithelium and the assembled neuroblasts. As development progressed, the axons formed later "selectively fasciculated" along the "pioneering" fibers in a staggered pattern as a result of their differential times of origin. These temporal and topographic patterns occurred in a manner such that the preexisting structure served as an "organizing structure" or foundation upon which the axonal processes formed later in the developmental sequence were oriented and assembled.