Pick me, Pick me! Rationale for investigating persistent inward currents (PICs) and associated exercise effects in the ageing neuromuscular system.

Abstract

The loss of neuromuscular function with ageing has been extensively documented. Physiologically, muscular fibre atrophy, loss and denervation along with associated motor unit remodelling occur with, and continue into, ageing. Although motor unit remodelling serves to reinnervate and preserve local muscle fibres and thus function, overall reductions in muscle strength and power are linked to greater risk of falling, associated co-morbidities and all-cause mortality amongst elderly individuals. However, the neuromuscular system (muscle and neural motor pathways) displays remarkable plastic potential. In particular, exercise serves as an important stimulus to increase muscle mass, strength and power and to improve overall neuromuscular function across the lifespan. As such, there is an ever-growing focus on the implementation of appropriately structured and targeted exercise programmes to combat age-related declines in neuromuscular function in older adults. Despite this, the effects of chronic exercise over the course of much of the lifespan are less clear. This poor understanding is likely compounded by the obvious difficulties (e.g. time requirements, logistics, participant retention) in conducting extreme longitudinal intervention studies. Thus, current research has largely sought to investigate the effects of lifelong exercise on the neuromuscular system by adopting well-controlled cross-sectional methodological designs.