Nociceptor (nociceptive nerve fiber)

Nociceptors, commonly referred to as pain fibers, are specialized primary sensory neurons that detect and transmit signals from noxious thermal, mechanical, or chemical stimuli to the central nervous system. They exist as heterogeneous populations, including myelinated Aδ fibers (mediate sharp, immediate “first pain”) and unmyelinated C fibers (mediate dull, delayed “second pain”). These fibers express various transducer proteins and ion channels such as TRPV1 (the capsaicin/vanilloid receptor), TRPA1, and acid-sensing ion channels (ASICs), which enable them to respond to a broad range of noxious stimuli[1][2][3][4]. Neuropeptides like CGRP and substance P are released from nociceptors and play roles in inflammation and pain amplification. As an anatomical/phenotypic entity rather than a molecular one, "pain fibers" do not represent a single therapeutic target, but components expressed by these fibers (such as TRPV1) are pursued as discrete drug targets in pain management[1][2][3].

Other names

pain fiberpain nerve fibersensory fiber (in the context of pain)nociceptive fiberprimary afferent nociceptor

Blockade or desensitization of specific ion channels (e.g., TRPV1 antagonism by certain drugs); Inhibition of action potential propagation (local anesthetics inhibiting voltage-gated sodium channels); Modulation of neurotransmitter/neuropeptide release