ABSTRACT
Recently, there has been considerable attention focused on the multipotent progenitor cells existing in ependymal and subependymal layer. However, almost all results have been derived from brain or injured CNS researches. So, the studies on the developmental characteristics of intact spinal ependymal layer have been relatively ignored. In the present study, we labeled rat spinal cord with nestin, bromodeoxyuridine (BrdU), and glial fibrillary acidic protein (GFAP) antibodies in order to track the differentiation and proliferative capacity of rat ependymal layer cells according to their developmental stages. At embryonic day 14 (E14), a number of cells in the spinal ependymal layer, especially constituting the alar and basal plates, showed extensive nestin immunoreactivities (ir). They also showed active proliferative capacities, because many nuclei of nestin-ir cells were also BrdU-ir. From postnatal day 0 (P0), nestin-ir cells were almost completely disappeared, and from P7, no nestin-ir cells could be detected. However, BrdU-ir nuclei continued to be identified until P14. These results suggested that the cells in the spinal ependymal layer retain their proliferative capacity until later stage of development. On the other hand, no GFAP-ir cells could be identified in the ependymal layer in our experimental period.