LAUSR

The human pharynx is a compliant conduit for airflow, vulnerable at times to collapse, owing to suction forces generated during inspiration. Repeated obstructions of the upper airway occur during sleep, giving rise to obstructive sleep apnoea syndrome (OSAS), which is very common (Benjafield et al., 2019). Obstructive sleep apnoea syndrome is a debilitating condition associated with a broad portfolio of morbidities, including cardiometabolic and neurocognitive impairments. Untreated OSAS increases the risk of premature death. Multiple factors contribute to airway vulnerability and propensity for arousal from sleep, resulting in a growing recognition of different OSAS endotypes. Additionally, lifestyle factors are important determinants of the propensity for airway occlusive events. Alcohol is a known depressant, and consumption worsens the severity of OSAS, measured as an increase in the number of obstructive events per hour of sleep. Studies in animals (Vecchio et al., 2010) and humans (Krol et al., 1984) have demonstrated that alcohol decreases tongue (genioglossus) EMGactivity, revealing an inhibitory influence onmotor control of upper airway muscles, which might relate to direct actions on cranial motor neurons innervating the tongue and/or depression of supramedullary excitatory inputs to cranial (hypoglossal) motor neurons. In this issue of Experimental Physiology, Avraam et al. (2023) describe, for the first time, the influence of acute alcohol ingestion on subpopulations of genioglossus motor units in healthy human participants, with an expectation that differential effects on subclasses of units would be revealed.