Microneurography as a tool to study the function of individual C-fiber afferents in humans: responses from nociceptors, thermoreceptors, and mechanoreceptors

• The technique of microneurography-recording neural traffic from nerves in awake humans-has provided us with unrivaled insights into afferent and efferent processes in the peripheral nervous system for over 50 years. We review the use of microneurography to study single C-fiber afferents and provide an overview of the knowledge gained, with views to future investigations. C-fibers have slowly conducting, thin-diameter, unmyelinated axons and make up the majority of the fibers in peripheral nerves (similar to 80%). With the use of microneurography in humans, C-fiber afferents have been differentiated into discrete subclasses that encode specific qualities of stimuli on the skin, and their functional roles have been investigated. Afferent somatosensory information provided by C-fibers underpins various positive and negative affective sensations from the periphery, including mechanical, thermal, and chemical pain (C-nociceptors), temperature (C-thermoreceptors), and positive affective aspects of touch (C-tactile afferents). Insights from microneurographic investigations have revealed the complexity of the C-fiber system, methods for delineating fundamental C-fiber populations in a translational manner, how C-fiber firing can be used to identify nerve deficits in pathological states, and how the responses from C-fibers may be modified to change sensory percepts, including decreasing pain. Understanding these processes may lead to future medical interventions to diagnose and treat C-fiber dysfunction. NEW & NOTEWORTHY The technique of microneurography allows us to directly investigate the functional roles of single C-fiber afferents in awake human beings. Here we outline and discuss the current field of C-fiber research on this heterogeneous population of afferents in healthy subjects, in pathological states, and from a translational perspective. We cover C-fibers encoding touch, temperature, and pain and provide perspectives on the future of C-fiber microneurography investigations in humans.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Fysiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Physiology (hsv//eng)

Nyckelord

C-fiber

mechanoreceptor

microneurography

nociception

pain

temperature

touch

mechano-insensitive nociceptors

unmyelinated tactile afferents

velocity recovery cycles

human-skin

electrical-stimulation

intraneural microstimulation

innervation territories

conduction-velocity

heat stimulation

low-temperature

Neurosciences & Neurology

Physiology

hmelz m

1995

experimental brain research

v104

p331

hmidt r

1995

journal of neuroscience

v15

p333

hmelz m

1994

journal of physiology-london

v480

p389

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)