C-fiber nociceptor (C-fiber) (C-fiber)

C-fiber nociceptors are a class of unmyelinated, small-diameter sensory neurons responsible for transmitting slow-onset, poorly localized pain, temperature, and itch signals from the periphery to the dorsal horn of the spinal cord [1][2]. These neurons are polymodal, responding to mechanical, thermal, and chemical stimuli through the expression of specific molecular transducers such as Transient Receptor Potential (TRP) channels and voltage-gated sodium channels (e.g., Nav1.7, Nav1.8) [3][4]. In chronic pain states, C-fibers often exhibit peripheral sensitization, where their activation threshold is lowered and their firing rate is increased, contributing to hyperalgesia and allodynia [5]. Pharmacological targeting of C-fibers typically involves the use of local anesthetics to block sodium channels or vanilloid agonists like capsaicin to induce functional desensitization or "defunctionalization" of the nerve terminals [6]. Understanding the distinct molecular profile of C-fibers is essential for developing selective analgesics that minimize central side effects and preserve motor function [4].

Other names

Group C nerve fiberUnmyelinated afferent fiberPolymodal nociceptorC-nociceptor

Drugs targeting C-fiber nociceptors primarily act by blocking voltage-gated sodium channels to inhibit action potential propagation, or by overstimulating TRPV1 receptors to induce calcium-mediated desensitization and temporary retraction of nerve terminals [3][6].