Ultrastructural studies of dorsal root axons regenerating through adult frog optic and sciatic nerves

摘要: Optic nerves of adult fish and amphibia can successfully regenerate, in part because their glial cells, unlike those mammals, provide an environment permissive to regrowth. We altered the regenerating dorsal root axons frog, Rana pipiens, by grafting segments optic nerve test permissiveness CNS cells other sensory neurons. compared these preparations grafts sciatic nerve. After allowing various times for survival, light electron microscopy were used evaluate grafts. An agglomeration astrocytes, tightly joined desmosomes, initially formed center Around this grew axons, accompanied Schwann cells. At early stages, some dilated terminal structures, which not seen peripheral The appearance blood vessels within graft dispersion allowed larger numbers grow through graft. By eight weeks, 48% had grown grafts, 84% These results suggest that astrocytes from are inhibitory to, a suitable substrate for, regrowing Microsc. Res. Tech. 46:310–318, 1999. © 1999 Wiley-Liss, Inc.