Problem: Peripheral nervous system (PNS) glial cells (Schwann cells) allow for regeneration of axons through the area of neural injury in cases of amputated limbs, but central nervous system (CNS) glial cells (oligodendrocytes) do not. How does this explain recovery from PNS and CNS nerve injuries? Investigate the differences between these cells, and try to come up with a solution or two for CNS injury based on your research.