The scientific community continues to work on ways to spur or guide nerve regeneration, something that doesn't normally occur to any great degree in human tissues. Much of that focus is on spinal injuries, and here researchers have found a way to use one cell type to guide the regrowth of others:
Transplanting self-donated Schwann cells (SCs, the principal ensheathing cells of the nervous system) that are elongated so as to bridge scar tissue in the injured spinal cord aids hind limb functional recovery in rats modeled with spinal cord injury. "Injury to the spinal cord results in scar and cavity formation at the lesion site. Although numerous cell transplantation strategies have been developed to nullify the lesion environment, scar tissue - in basil lamina sheets - wall off the lesion to prevent further injury and, also, at the interface, scar tissue impedes axon regeneration into and out of the grafts, limiting functional recovery."
The researchers determined that the properties of a spinal cord/Schwann cell bridge interface enable regenerated and elongated brainstem axons to cross the bridge and potentially lead to an improvement in hind limb movement of rats with spinal cord injury. Electron microscopy revealed that axons, SCs, and astrocytes were enclosed together within tunnels bounded by continuous basal lamina. The expression of neuroglycan (NG2; a proteoglycan found on the membrane of cells) was associated with these tunnels. They subsequently determined that a "trio" of astrocyte processes, SCs and regenerating axons were "bundled" together within the tunnels of basal lamina.