Motor unit changes in normal aging: a brief review.

Aging is explored by multiple lines of research, in a pursuit of understanding this natural process. The motor response is usually the main dependent variable in studies regarding physical or cognitive decline in aging. It is therefore critical to understand how the motor function changes with age. The present review, aims at presenting briefly some of the most recently published works in the field, focusing on the three key components of the motor unit. The changes that the skeletal muscle undergoes aging sarcopenia, alteration of fiber type distribution and also intimate metabolic transformations. The neuromuscular junction suffers at cellular and molecular level, with possible implications of various cell components, mediators and oxidative stress. Motoneuron loss and change in their physiological properties accompany remodeling in the motor units. The applicability of knowledge in this field lies in possible interventions intended to counteract these age-related losses.