Peripheral sensory C-fibers of the vagus nerve (Vagal C-fibers)

Peripheral sensory C-fibers of the vagus nerve are unmyelinated, slow-conducting afferent neurons that provide essential sensory feedback from the thoracic and abdominal viscera to the nucleus tractus solitarius in the brainstem (Mazzone & Undem, 2016, Chemical Senses). These fibers are equipped with a variety of receptors and ion channels, such as TRPV1 and P2X3, allowing them to detect chemical, mechanical, and thermal stimuli (Undem & Kollarik, 2005, Journal of Physiology). In healthy states, they regulate vital autonomic functions and protective reflexes, including the cough reflex and satiety. However, pathological hypersensitivity of these fibers is a key driver in conditions like chronic refractory cough, where they respond excessively to non-noxious stimuli (Morice et al., 2021, European Respiratory Review). Therapeutic strategies include pharmacological inhibition of specific channels on these fibers, such as the P2X3 antagonist gefapixant, or the use of vagus nerve stimulation (VNS) to modulate their signaling patterns for treating epilepsy, depression, and inflammatory disorders (Bonaz et al., 2018, Frontiers in Neuroscience).

Other names

Vagal afferent C-fibersUnmyelinated vagal afferentsBronchopulmonary C-fibersGastric C-fibersPulmonary C-fibersVagal nociceptors

Modulation of neuronal excitability through the inhibition or activation of specific ion channels (e.g., P2X3, TRPV1, Nav1.7) and receptors expressed on the fiber membrane, or through direct electrical stimulation to alter afferent signaling to the brainstem.