The role of walking exercise on axonal regrowth and neuropathic pain markers in dorsal root ganglion after sciatic nerve injury

The aim of this study was to determine whether walking exercise can regulate the expression level of neuropathic pain- and inflammatory re-sponse markers in the ipsilateral lumbar 4 to 6 dorsal root ganglion neu-rons after sciatic nerve injury (SNI). The experimental rats were ran-domly divided into seven groups: the normal control group, sedentary groups for 3, 7, and, 14 days postinjury (dpi), and walking exercise groups for 3, 7, and 14 dpi. Western blot techniques were used to evaluate spe-cific neuropathic pain- and cytokine markers and mechanical allodynia was confirmed by paw withdrawal test. Mechanical allodynia was sig-nificantly improved in the walking exercise group compared to the sed-entary group at all 7, 10, and 14 dpi. Furthermore, growth associated protein 43 and brain-derived neurotrophic factor levels were signifi-cantly increased in the walking exercise groups compared to the sed-entary group at all 3, 7, and 14 dpi. Conversely, nuclear factor kappa-light-chain-enhancer of activated B cells, interleukin-6, tumor necrosis factor α, calcitonin gene-related peptide, and c-Fos expression levels were significantly decreased in the walking exercise groups compared to the sedentary group at all 3, 7, and 14 dpi. These findings suggest meaning-ful information that aggressive rehabilitation walking exercise applied early after SNI might be improve mechanical allodynia, neuropathic pain and inflammatory response markers following SNI.