The Journal of Physiology, Год журнала: 2025, Номер unknown

Опубликована: Март 17, 2025

Abstract The neuromuscular junction (NMJ) plays a key role in modulating muscle contraction, but the impact of short‐term disuse on NMJ structure and function, particularly older humans, remains unclear. This study aimed to investigate alterations following 10 days horizontal bed rest males (68.5 ± 2.6 years). Before after rest, vastus lateralis biopsies were obtained evaluate morphology, intramuscular EMG (iEMG) was recorded assess function blood samples collected determine circulating C‐terminal agrin fragment (CAF) concentration, biomarker remodelling. In sub‐cohort six participants who had NMJs both pre‐ post‐bed biopsies, we observed altered including reduced overlap between terminals, as well increased endplate area perimeter. CAF concentration elevated suggesting ongoing iEMG analysis showed motor unit potential complexity firing rate. addition, impaired transmission, inferred from near‐fibre jiggle segment jitter. These findings suggest that male individuals are susceptible remodelling transmission with disuse, providing valuable insights into morphological functional consequences inactivity an ageing population. Our highlights importance developing interventions for mitigating detrimental health adults, which they frequently experience injury, trauma, illness or surgery. image Key points is crucial signal motoneuron skeletal muscle, linked several disorders, ageing. However, structural integrity NMJ, largely unknown. We used model morphology men. hypothesised day period would lead transmission. show sufficient induce marked associated changes properties. vulnerable dysfunction response emphasise maintaining active lifestyle preserving

Язык: Английский