Plasticity of gastro-intestinal vagal afferent endings

• Vagal afferent plasticity occurs in a normal day to day manner as well as in response to metabolic perturbations.
• Vagal afferent function is modulated by factors including nutrients, hormones, circadian signals and the gut microbiota.
• Diet induced obesity reduces vagal afferent satiety signals induced by mechanical and peptide signals.
• The highly plastic nature of vagal afferents makes them a desirable peripheral target for the treatment of obesity.

Vagal afferents are a vital link between the peripheral tissue and central nervous system (CNS). There is an abundance of vagal afferents present within the proximal gastrointestinal tract which are responsible for monitoring and controlling gastrointestinal function. Whilst essential for maintaining homeostasis there is a vast amount of literature emerging which describes remarkable plasticity of vagal afferents in response to endogenous as well as exogenous stimuli. This plasticity for the most part is vital in maintaining healthy processes; however, there are increased reports of vagal plasticity being disrupted in pathological states, such as obesity. Many of the disruptions, observed in obesity, have the potential to reduce vagal afferent satiety signalling which could ultimately perpetuate the obese state. Understanding how plasticity occurs within vagal afferents will open a whole new understanding of gut function as well as identify new treatment options for obesity.