Small-diameter skin nerve fiber

Small-diameter skin nerve fibers are primarily unmyelinated or thinly myelinated peripheral nerves that innervate the skin. The most well-characterized type is the **C fiber**, which has a diameter typically less than 1.5 micrometers and conducts impulses slowly due to lack of myelin. These fibers are responsible for transmitting sensory information such as pain (nociception), temperature, itch, and some autonomic signals from the periphery to the central nervous system. They play a crucial role in detecting injury or illness through sensations like burning pain and warmth. Dysfunction or damage to these fibers can result in small-fiber neuropathy, characterized by altered pain perception and autonomic symptoms. Capsaicin is known to activate vanilloid receptors on these fibers, producing characteristic burning sensations associated with chili peppers. Note on correctness: "Narrow-diameter skin nerve fibers" is not a canonical molecular target but rather describes a class of anatomical structures—primarily small unmyelinated C fibers—in peripheral nerves. It does not refer to a single protein or receptor but rather an entire population of functionally similar axons; thus it should not be considered a therapeutic target in the conventional sense used for drug discovery (e.g., receptor proteins).

Other names

Small fiberC fiberUnmyelinated nerve fiberSmall-diameter peripheral nerve fiber

Activation of vanilloid receptors on C fibers by capsaicin causes burning pain sensation