Summary

The freedom to move, to be able to celebrate one's existence through dance, is a grand gift of nature enjoyed by humankind. Yet this gift can be lost all too readily; injury, particularly near the proximal regions of peripheral nerves, can increase the risk of permanent paralysis. The clinical rate of nerve regeneration is approximately 1 mm per day and 1–2 years may be required for axons to traverse from the proximal to the distal reaches of limbs. During such prolonged denervation, motor (Gutmann and Young, 1944; Drachman et al., 1967; Miledi and Slater, 1969) and sensory (Tower, 1932; Kubota et al., 1978; Barker et al., 1986) end-organs may undergo servere atrophy and degenerate to such an extent that successful reinnervation may no longer be possible. For example, the loss of muscle fiber can be essentially complete and only adipose and connective tissues remain (Gutmann and Zelena, 1962). Prolonged disconnection from target end-organs is also detrimental to neurons and motor neurons are eventually lost when axotomy is permanent (Kawamura and Dyck, 1981).