Arthritis and Pain. Neurogenic origin of joint pain
Department of Physiology & Biophysics, University of Calgary, Hospital Drive, Calgary, Alberta, T2N 4N1, Canada
Arthritis Research & Therapy 2006, 8:220 doi:10.1186/ar2069Published: 10 November 2006
Arthritis pain affects millions of people worldwide yet we still have only a limited understanding of what makes our joints ache. This review examines the sensory innervation of diarthroidal joints and discusses the neurophysiological processes that lead to the generation of painful sensation. During inflammation, joint nerves become sensitized to mechanical stimuli through the actions of neuropeptides, eicosanoids, proteinase-activated receptors and ion channel ligands. The contribution of immunocytes to arthritis pain is also reviewed. Finally, the existence of an endogenous analgesic system in joints is considered and the reasons for its inability to control pain are postulated.