Peripheral nociceptive mechanisms in an experimental rat model of fibromyalgia induced by repeated cold stress

Publication date: Available online 28 December 2019Source: Neuroscience ResearchAuthor(s): Koji Wakatsuki, Yoshiko T.-Uchimura, Takanori Matsubara, Teruaki Nasu, Kazue Mizumura, Toru TaguchiAbstractFibromyalgia (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 sugg...
Source: Neuroscience Research - Category: Neuroscience Source Type: research