title: Voluntary Exercise Training: Analysis of Mice in Uninjured, Inflammatory, and Nerve-Injured Pain States.
abstract: Both clinical and animal studies suggest that exercise may be an effective way to manage inflammatory and neuropathic pain conditions. However, existing animal studies commonly use forced exercise paradigms that incorporate varying degrees of stress, which itself can elicit analgesia, and thus may complicate the interpretation of the effects of exercise on pain. We investigated the analgesic potential of voluntary wheel running in the formalin model of acute inflammatory pain and the spared nerve injury model of neuropathic pain in mice. In uninjured, adult C57BL/6J mice, 1 to 4 weeks of exercise training did not alter nociceptive thresholds, lumbar dorsal root ganglia neuronal excitability, or hindpaw intraepidermal innervation. Further, exercise training failed to attenuate formalin-induced spontaneous pain. Lastly, 2 weeks of exercise training was ineffective in reversing spared nerve injury-induced mechanical hypersensitivity or in improving muscle wasting or hindpaw denervation. These findings indicate that in contrast to rodent forced exercise paradigms, short durations of voluntary wheel running do not improve pain-like symptoms in mouse models of acute inflammation and peripheral nerve injury.
authors.affiliation: Washington University Pain Center and Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri, United States of America; Washington University Program in Neuroscience, Washington University School of Medicine, St. Louis, Missouri, United States of America.
authors.forename: Tayler D
authors.initials: TD
authors.lastname: Sheahan
authors.affiliation: Washington University Pain Center and Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri, United States of America.
authors.forename: Bryan A
authors.initials: BA
authors.lastname: Copits
authors.affiliation: Washington University Pain Center and Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri, United States of America.
authors.forename: Judith P
authors.initials: JP
authors.lastname: Golden
authors.affiliation: Washington University Pain Center and Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri, United States of America; Washington University Program in Neuroscience, Washington University School of Medicine, St. Louis, Missouri, United States of America.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Gereau
mesh_terms: D000818:Animals; D005081:Exercise Therapy; D005727:Ganglia, Spinal / Q000502:physiology; D007249:Inflammation / Q000628:therapy; D051379:Mice; D008810:Mice, Inbred C57BL; D009437:Neuralgia / Q000628:therapy*; D017288:Pain Threshold; D059348:Peripheral Nerve Injuries / Q000628:therapy*; D005082:Physical Exertion