Peripheral nociceptive mechanisms in an experimental rat model of fibromyalgia induced by repeated cold stress. (January 2021)

• Record Type: Journal Article
• Authors: Wakatsuki, Koji; T.-Uchimura, Yoshiko; Matsubara, Takanori; Nasu, Teruaki; Mizumura, Kazue; Taguchi, Toru
• Is Part Of: Neuroscience research. Volume 162(2021)
• Page Start: 22
• Page End: 30
• Publication Date: 2021-01
• Subjects: FM fibromyalgia -- RCS repeated cold stress -- ICS intermittent cold stress -- SART specific alteration of rhythm in temperature -- EDL extensor digitorum longus muscle -- RF receptive field -- CV conduction velocity -- NGF nerve growth factor -- GDNF glial cell line-derived neurotrophic factor -- BDNF brain-derived neurotrophic factor -- NT-3 neurotrophin-3 -- IL-1β interleukin-1β -- IL-6 interleukin-6 -- TNF-α tumour necrosis factor-α -- SFN small fiber neuropathy; Repeated cold stress -- Fibromyalgia -- Mechanical -- Hyperalgesia -- Chronic widespread pain -- Muscular nociceptors -- C-fibers -- Single-fiber recording -- Neurotrophic -- Factors; Neurosciences -- Research -- Periodicals; Neurosciences -- Research -- Japan -- Periodicals; Neurology -- Periodicals; Neurosciences -- Periodicals; Neurosciences -- Recherche -- Périodiques; Neurosciences -- Recherche -- Japon -- Périodiques; Neurosciences -- Research; Japan; Periodicals; 612.8
• DOI: 10.1016/j.neures.2019.12.015
• Languages: English
• ISSNs: 0168-0102

Abstract

Highlights: Peripheral neural mechanisms of fibromyalgia (FM) were examined using a rat FM model. Muscular nociceptors were sensitized to mechanical stimulation in the FM model. Thermal responsiveness and general characteristics of nociceptors were unchanged. Muscular mRNAs of neurotrophic factors and inflammatory mediators were unchanged. The facilitated muscular nociceptors could be a target for the treatment of FM. Abstract: Fibromyalgia (FM) is a debilitating disease characterized by generalized and persistent musculoskeletal pain. Although central mechanisms are strongly implicated in the pathogenesis of FM, the involvement of peripheral mechanisms is poorly understood. To understand the peripheral nociceptive mechanisms, we examined muscular nociceptors in an FM model, which was made by exposing rats to repeated cold stress (RCS). A single muscle C-fiber nociceptors were identified through the teased fiber technique using ex vivo muscle-nerve preparations. Response properties of C-fibers to noxious stimuli were systematically analyzed. Messenger RNA expression of neurotrophic factors and inflammatory mediators were also studied in the muscle. In the RCS group, the mechanical response threshold of C-fibers, measured using a ramp mechanical stimulus, was significantly decreased, and the response magnitude was significantly increased in the RCS group when compared with the SHAM group, where the environmental temperature was not altered. The general characteristics of C-fibers and the responsiveness to noxious cold and heat stimuli were similar between the two groups. Messenger RNAs of neurotrophic factors and inflammatory mediators were not changed in the muscle during and after RCS. These results suggest that augmentation of the mechanical response of muscle C-fiber nociceptors contributes to hyperalgesia in the RCS model.