Anatomically the position of the genioglossus muscle and its role in dilating the airway is of great interest in understanding the pathogenesis of obstructive sleep apnea. The tongue also plays a critical role in swallowing and speech pathologies ; therefore, understanding how the neuromuscular innervation may be remodeled with aging is clinically important and may provide insight for therapy or treatment based on age. WZ8040 changes that occur within the pharyngeal musculature with aging remain incompletely understood. Despite the fact that the genioglossus muscle is known to contain a high proportion of Type II muscle fibers and aging effects are pronounced for Type II fibers, we recently found no evidence for increased MUP durations associated with age in humans. While some investigators have found a continuous increase of MUP durations in skeletal muscles from 1 year of life up to 80 years other investigators have demonstrated that the aging effect on MUP duration occurs predominantly after 55 years of age. Previously, we reported neural injury associated with obstructive sleep apnea patients, observed by an increase in the durations of MUPs of the genioglossus muscle of humans. However, these investigations were not specifically targeted to investigate aging, as we included primarily younger adults. Limited information exists about changes in the morphology of MUPs with aging. Based on the aging literature compensatory adaptation with muscle fiber hypertrophy or neurogenic changes such as collateral sprouting of motor axons may occur indicating a remodelling of the motor units. We aimed to investigate the effect of aging, in genioglossus muscle, with a range of conventional and specialized electromyographic techniques to obtain features of EMG signals that relate to one or more aspects of normal and pathologic function. Thus, we measured the activity from the genioglossus in younger and older adults while they were awake and breathing quietly. Based on the MUP literature we hypothesized that MUPs detected in older adults would show signs for greater degrees of reinnervation. This study clearly demonstrates age-related changes in motor unit potentials detected in the genioglossus muscle. We found evidence for remodeling suggesting denervation, collateral sprouting and reinnervation of orphaned muscle fibers leading to increased motor unit size, spatial dispersion of motor unit territories and, size and temporal dispersion of motor unit potential components in older adults.