Abstract
Several recent publications describe remarkably promising effects of transplanting olfactory ensheathing cells as a potential future method to repair human spinal cord injuries. But why were cells from the nose transplanted into the spinal cord? What are olfactory ensheathing cells, and how might they produce these beneficial effects? And more generally, what do we mean by spinal cord injury? To what extent can we compare repair in an animal to repair in a human?