The Case for Adaptability of the Neuromuscular Junction to Endurance Exercise Training

Abstract

Although the adaptability of the neuromuscular junction (NMJ) has been demonstrated using the models of denervation/reinnervation, electrical stimulation, development, aging, and pathological states, relatively little is known about the effects of increased chronic voluntary use on the morphology and physiological function of the NMJ. A review of findings relating to adaptations in the various pre- and postsynaptic components of the NMJ with exercise training is presented. These findings are discussed as they pertain to NMJ function during exercise. Other physiological modulators of the NMJ, such as trophic factors released by nerve terminals and muscles, and circulating substances are discussed in terms of possible roles they may play in training-induced adaptations. Key words: neuromuscular junction, endurance exercise, adaptations, morphology, acetylcholinesterase, physiology, trophic factors