The Neuromuscular Junction: A Shared Vulnerability in Aging and Disease.

The neuromuscular junction (NMJ) is a specialized synapse essential for effective motor neuron-muscle communication and is increasingly recognized as a vulnerable site in aging and neuromuscular disease. While traditionally considered a final common pathway for motor deficits, accumulating evidence demonstrates that NMJ dysfunction is an early and critical driver of disease onset and progression in conditions such as amyotrophic lateral sclerosis and Charcot-Marie-Tooth disease. This review highlights shared and disease-specific mechanisms contributing to NMJ impairment, including presynaptic, postsynaptic, and perisynaptic Schwann cell defects in these diseases. We also discuss age-related changes at the NMJ, emphasizing its role in sarcopenia and muscle weakness in older adults. Furthermore, we explore emerging molecular drivers of NMJ dysfunction uncovered through studies in congenital myasthenic syndromes, autoimmune disorders, and advanced omics approaches. By integrating insights across diseases and aging, we underscore the potential for shared therapeutic strategies aimed at stabilizing NMJ function. Promising interventions targeting presynaptic neurotransmitter release, postsynaptic excitability, and perisynaptic Schwann cells are discussed as avenues to improve neuromuscular transmission and maintain muscle strength. Finally, we discuss the challenges and opportunities in translating these mechanistic insights into clinical therapies and highlight how novel human neuromuscular organoid models and advanced molecular profiling can bridge this gap. Together, these insights establish the NMJ as a critical, modifiable target for preserving motor function across neuromuscular diseases and aging.