Nerve Regeneration in the Peripheral Nervous System (PNS) of mammals Es

INTRODUCTION Nerve Regeneration in the Peripheral Nervous System (PNS) of mammals PNS neurons in mammals have a capacity to regenerate and re innervate the target. However functional recovery varies, depending on the type and location of injury, age of the neurons and other factors, but the recovery is never complete. An overview of the regenerative response Following an injury, in the distal nerve stump a series of degenerative processes prepare the right environment needed for an effective regenerative response. The degenerated axons and myelin debris are removed by the surrounding Schwann cells (SCs) and invading macrophages. SCs proliferate and their basal lamina forms the endoneurial tube, through which the new axonal sprouts find their way to the target. The cell body also undergoes dramatic changes, triggered by the lack of signals that are retrogradely transported from the target. Within the cell body, certain genes and proteins are up regulated, such as growth associated proteins (GAPs), tubulin, and actin. Most of the cues involved in axonal regeneration are simi...