Slow touch and ultrafast pain fibres: Revisiting peripheral nerve classification.

Autor: Olausson H; Department of Biomedical and Clinical Sciences, Linköping University, Linköping 58185, Sweden. Electronic address: hakan.olausson@liu.se., Marshall A; School of Natural Sciences and Psychology, Liverpool John Moores University, L3 3AF Liverpool, UK., Nagi SS; Department of Biomedical and Clinical Sciences, Linköping University, Linköping 58185, Sweden., Cole J; University Hospitals, Dorset and Bournemouth University, Poole BH12 5BB, UK.
Jazyk: angličtina
Zdroj: Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology [Clin Neurophysiol] 2024 Jul; Vol. 163, pp. 255-262. Date of Electronic Publication: 2024 May 03.
DOI: 10.1016/j.clinph.2024.04.008
Abstrakt: One hundred years ago, Erlanger and Gasser demonstrated that conduction velocity is correlated with the diameter of a peripheral nerve axon. Later, they also demonstrated that the functional role of the axon is related to its diameter: touch is signalled by large-diameter axons, whereas pain and temperature are signalled by small-diameter axons. Certain discoveries in recent decades prompt a modification of this canonical classification. Here, we review the evidence for unmyelinated (C) fibres signalling touch at a slow conduction velocity and likely contributing to affective aspects of tactile information. We also review the evidence for large-diameter Aβ afferents signalling pain at ultrafast conduction velocity and likely contributing to the rapid nociceptive withdrawal reflex. These discoveries imply that conduction velocity is not as clear-cut an indication of the functional role of the axon as previously thought. We finally suggest that a future taxonomy of the peripheral afferent nervous system might be based on the combination of the axońs molecular expression and electrophysiological response properties.
(Copyright © 2024 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE