Although in the adult central nervous system (CNS) some potential for neurogenesis (in the gray matter) and axonal regrowth (in the white matter) exists, the response to stimulation (neuroplasticity) and injury (neuroregeneration) in the CNS is mainly based on a synaptic reorganization of the existing/surviving neurons and nerve fibers to cope with the new environmental conditions. By contrast, in the adult peripheral nervous system (PNS), adaptive neuroplasticity and axonal regeneration potential is much higher and is at the basis of the usually higher degree of recovery after peripheral nerve trauma (in comparison to CNS) provided that the continuity of the nerve is either maintained or, if lost, adequately reconstructed.