This rather dismal neurologic prognosis has stimulated significant research efforts to understand the neurobiology of spinal cord injury and develop effective therapies for it. This international effort has tremendously increased our understanding of the neuropathology of spinal cord injury and has shed much insight into the acute and chronic pathophysiologic processes that inhibit neural regeneration and functional recovery (reviewed by Kwon et al., 2002). The large majority of research into spinal cord repair strategies can be conceptually divided into two streams: