Vagal mechanoreceptors controlling gastrointestinal function.

The vagus nerve innervates internal organs, in particular the gastrointestinal tract, and is a major communication route between the gut and brain. Most vagal fibers are viscerosensory, but vagal motor axons also travel with the nerve. Vagal sensory neurons can detect mechanosensory information arising from the gastrointestinal tract such as stretch or pressure, and transmit this information to the nucleus of the solitary tract in the brain. Recent technological advances have opened new routes for studying vagal mechanosensation. Single-cell transcriptomic atlases have revealed substantial heterogeneity among vagal sensory neurons and now guide targeted analysis of individual subtypes. Viral and genetic approaches based on molecular profiling enable anatomical tracing, electrophysiological recordings, and selective ablation, silencing, or activation of defined neuronal populations. Recent work has revealed subtypes of vagal mechanoreceptors defined by expression of Prox2, Runx3, Glp1r, and Oxtr, which form intraganglionic laminar endings in the muscle layer of the gut. These mechanoreceptors detect distension in the gastrointestinal tract, such as a bolus moving through the esophagus or the filling of the stomach, and initiate coordinated peristalsis. Together, these mechanosensory pathways enable precise monitoring of gastrointestinal mechanics to support digestive function.