Role of C-tactile fibers in pain modulation: animal and human perspectives. (February 2022)

• Record Type: Journal Article
• Authors: Larsson, Max; Nagi, Saad S
• Is Part Of: Current opinion in behavioral sciences. Volume 43(2022)
• Page Start: 138
• Page End: 144
• Publication Date: 2022-02
• Subjects: Psychology -- Periodicals; 150.5
• DOI: 10.1016/j.cobeha.2021.09.005
• Languages: English
• ISSNs: 2352-1546

Abstract

Highlights: Human and animal studies suggest a possible role for C-LTMRs in allodynia. Activation of C-LTMRs may also alleviate pain in some contexts. Diverse synaptic and non-synaptic C-LTMR signals may bidirectionally modulate pain. Abstract : C-tactile (CT) fibers, a population of unmyelinated (C) fibers that respond particularly well to gentle stroking, are widely believed to subserve affective touch. However, these fibers (termed C low-threshold mechanoreceptors (C-LTMRs) in non-human mammals) have also been proposed to be involved in the modulation of pain. Intriguingly, functional evidence from both human and animal studies indicates that CT/C-LTMR fibers can both contribute to allodynia as well as mediate pain inhibition. In the spinal cord, C-LTMR fibers form glomerular synaptic arrangements, providing input to several populations of interneurons within the nociceptive circuitry. Thus, the CT/C-LTMR system conveys signals that are subject to intricate processing in the spinal cord and is well-situated within spinal sensory pathways to enable the modulation of pain.