Sedentary aging results in structural impairment of the neuromuscular junction and may be attenuated by voluntary endurance exercise

Abstract

An increasingly prominent change in the aging body is the decrease in muscle mass and strength, a condition known as sarcopenia. This is a major cause for the instability in elderly individuals leading to falls and injuries. One possible cause of sarcopenia is the reduced exercise activity of older individuals. The neuromuscular junction (NMJ) is the connection by which nerves control muscle movement. This study mainly aims to investigates the possibility that alterations in the structures of the neuromuscular junction with ageing might contribute to impaired control and physical maintenance of aging muscle. Changes in the NMJ include the loss of nerve terminal from the postsynaptic membrane leading to denervation and fragmentation of postsynaptic clusters of acetylcholine receptors (AChRs) resulting in tiny islands of receptors. Exercise in ageing animals and humans have shown to have some positive effects on sarcopenic related changes like slowing down the rate of loss in muscle mass and strength. In the neuromuscular junction of old animals and rodents that exercised the age related changes were reported to be less severe and in some cases the NMJ recovered.