These inhibitors appear to be concentrated in myelin, a material that wraps around spinal axons and improves conduction. Implantation of cells that produce IN-1 in rats promoted spinal cord regeneration. Diverting regenerating axons into gray matter . Cheng and Olson's work lends credence to Schwab's finding that WM inhibits growth, demonstrates that axons can grow long distances in GM, and provides a potential surgical approach to reconnecting transected spinal cords. Building cellular bridges .
Several studies suggest that it is possible to use other cells and materials to bridge the gap.
Doug Anderson and Paul Reier at the University of Florida at Gainesville transplanted fetal spinal cords to the injury site in humans, based on the notion that fetal cells might support growth. These studies showed that fetal cells will survive at the injury site and will support some growth. Two patients received fetal cell transplants last year in Florida and dozens have received such transplants in Sweden and Russia. Results from this procedure have been inconclusive so far. Mary Bunge and colleagues at the Miami Project have been using artificial bridges and Schwann cells.