ABSTRACT
The adult mammalian central nervous system (CNS), especially the spinal cord, has been considered a representative example of an organ in which regeneration is diffi cult. However, in 1992, Reynolds, and Weiss identifi ed cells with the potential to generate new neurons or neural stem cells, which they named neurospheres (Reynolds and Weiss 1992). Subsequently, methods were established to culture mammalian neural stem/progenitor cells (NS/PCs) from animals, and humans (Davis and Temple 1994; Kilpatrick and Bartlett 1993; Palmer et al. 1995). Since the report that the transplantation of fetal spinal cord tissue leads to functional recovery from spinal cord injury (SCI) in the rat (Bregman et al. 1993), NS/PCs have been considered an effective cell source for transplantation therapy in SCI. Recently, stem cell based approaches such as NS/PC transplantation have been further identifi ed as promising therapies for various CNS disorders (Bjorklund and Lindvall 2000; Gage 2000; Lindvall and Kokaia 2006).
