Regenerative medicine for the central nervous system - Transplantation of neural stem cells into the injured spinal cord -

Advances in the stem cell biology of the central nervous system (CNS) and other studies enhance the possibility of regeneration of the damaged CNS, which has previously been considered to be almost impossible. The availability of signals to induce the appropriate differentiation of the transplanted and/or endogenous neural stem cells (NSCs) as well as the timing of the transplantation are vital factors for improving the functional recovery of the damaged CNS. Because the immediate post-traumatic microenvironment of the spinal cord is in an acute inflammatory stage, it does not favor the survival and differentiation of the transplants. Furthermore, in the chronic disease stage after injury, glial scars that inhibit the regeneration of neuronal axons form in the injured site. Thus, we consider that the optimal period of transplantation is 1-2 weeks after injury.