Brief electrical stimulation accelerates axon regeneration in the peripheral nervous system and promotes sensory axon regeneration in the central nervous system.
Injured peripheral but not central nerves regenerate their axons but functional recovery is often poor. We demonstrate that prolonged periods of axon separation from targets and Schwann cell denervation eliminate regenerative capacity in the peripheral nervous system (PNS). A substantial delay of 4 weeks for all regenerating axons to cross a site of repair of sectioned nerve contributes to the long period of separation. Findings that 1h 20Hz bipolar electrical stimulation accelerates axon outgrowth across the repair site and the downstream reinnervation of denervated muscles in rats and human patients, provides a new and exciting method to improve functional recovery after nerve injuries. Drugs that elevate neuronal cAMP and activate PKA promote axon outgrowth in vivo and in vitro, mimicking the electrical stimulation effect. Rapid expression of neurotrophic factors and their receptors and then of growth associated proteins thereafter via cAMP, is the likely mechanism by which electrical stimulation accelerates axon outgrowth from the site of injury in both peripheral and central nervous systems.
Gordon
Tessa
T
Division of Physical Medicine and Rehabilitation, University of Alberta, Edmonton, Alberta.
Udina
Esther
E
Verge
Valerie M K
VM
de Chaves
Elena I Posse
EI
D000818:Animals; D001369:Axons / Q000378:metabolism; D019771:Axotomy; D004195:Disease Models, Animal; D004525:Efferent Pathways; D004599:Electric Stimulation Therapy; D006801:Humans; D009416:Nerve Regeneration; D009482:Neurophysiology; D059348:Peripheral Nerve Injuries; D010523:Peripheral Nervous System Diseases / Q000534:rehabilitation*; D051381:Rats; D020127:Recovery of Function; D013997:Time Factors