In recent years, various studies have been conducted toward the goal of achieving regeneration of the central nervous system using neural stem cells. However, various complex factors are involved in the regulation of neural stem cell differentiation, and many unresolved questions remain. It has been reported that after spinal cord injury, the intrinsic neural stem cells do not differentiate into neurons but, rather, into astrocytes, resulting in the formation of glial scars. Based on reports that the expression of interleukin (IL)-6 and the IL-6 receptor (IL- 6R) is sharply increased in the acute stages after spinal cord injury and that IL-6 may serve as a factor strongly inducing the differentiation of neural stem cells into astrocytes, we examined the effects of an antibody to IL-6R in cases of spinal cord injury and found that the antibody suppressed secondary injury (caused by inflammatory reactions) and glial scar formation, facilitating functional recovery. This article presents the data from this investigation and discusses the relationship between IL-6 signals and spinal cord injury.