 Wallerian degeneration is a process that occurs before nerve regeneration and can be described as a cleaning or clearing process that essentially prepares the distal stump for reinnervation.Schwann cells are glial cells in the peripheral nervous system that support neurons by forming myelin that encases nerves.During Wallerian degeneration Schwann cells and macrophages interact to remove debris, specifically myelin and the damaged axon, from the distal injury site.