Stress-induced modulation of vagal afferents

Vagally dependent gastric functions, including motility, tone, compliance, and emptying rate, play an important role in the regulation of food intake and satiation. Vagal afferent fibers relay sensory information from the stomach, including meal-related information, centrally and initiate co-ordinated autonomic efferent responses that regulate upper gastrointestinal responses. The purpose of this mini-review is to highlight several recent studies which have uncovered the remarkable degree of neuroplasticity within gastric mechanosensitive vagal afferents and the recent study by Li et al, in this issue of Neurogastroenterology and Motility, who show that the mechanosensitivity of gastric vagal afferents is dysregulated in a murine model of chronic stress. The authors demonstrate that both gastric mucosal and tension afferents are hypersensitive following chronic stress, and responses to mucosal stroking and muscle stretch are enhanced significantly. As gastric distension and volumetric signaling is important in satiety signaling and meal termination, this may provide a mechanistic basis for the gastric hypersensitivity associated with stress-associated clinical problems such as functional dyspepsia.