Motor Unit Remodeling

Abstract

To fully appreciate the contribution of motor unit (MU) remodeling to sarcopenia, a reminder of the basic structure and function of the neuromuscular system is described. The nervous system regulates MU recruitment and allows an older adult to carry out a range of movements from fast and powerful to small and subtle. Adaptations to the neuromuscular system are marked by aging and are evidenced by direct quantification of MUs from human cadavers or indirectly by estimating MU numbers via electrophysiological techniques. The loss of MU largely correlates with the loss of muscle fibers in aging. The decline in MU firing capacity can significantly impede an older adult’s ability to carry out act..