Abdolreza Kazemi - Department of Physical Education and Sports Sciences, Faculty of Humanity and Literature, Vali E Asr University of Rafsanjan, Rafsanjan, Iran
Masoud Rahmati - Departments of Physical Education and Sports Sciences, Lorestan University, Khoram Abad, Iran
Rasoul Eslami - Department of corrective exercise and Sports injury, Faculty of Physical Education and Sports Sciences, Allameh Tabataba’i University, Tehran, Iran
Vahid Sheibani - Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran

Objective(s): Neurotrophins (NTs) exert various effects on neuronal system. Growing evidence indicates that NTs are involved in the pathophysiology of neuropathic pain. However, the exact role of these proteins in modulating nociceptive signaling requires being defined. Thus, the aim of this study was to evaluate the effects of spinal nerve ligation (SNL) on NTs activation in the lumbar dorsal root. Materials and Methods: Ten male Wistar rats were ran domly assigned to two groups: tight ligation of the L۵ spinal nerve (SNL: n=۵) and Sham (n=۵). In order to produce neuropathic pain, the L۵ spinal nerve was tightly ligated (SNL). Then, allodynia and hyperalgesia tests were conducted weekly. After ۴ weeks, tissue samples were taken from the two groups for laboratory evaluations. Here, Real-Time PCR quantity method was used for measuring NTs gene expression levels. Results: SNL resulted in a significant weight loss in the soleus muscle (P<۰.۰۵), mechanical allodynia and thermal hyperalgesia thresholds (respectively, P<۰.۰۵; P<۰.۰۵). Also, NGF, NT-۴, NT-۳, TrkA, TrkB and TrkC expression were up-regulated following spinal nerve ligation group (respectively, P=۰.۰۲۵, P=۰.۰۱۳, P=۰.۰۰۱, P=۰.۰۰۲, P<۰.۰۰۱, P=۰۰۱) (respectively, ۴.۷, ۵.۲, ۷.۵, ۵.۱, ۷.۲, ۶.۲ folds). Conclusion: The present study provides new evidence that neuropathic pain induced by spinal nerve ligation probably activates NTs and Trk receptors expression in DRG. However, further studies are needed to better elucidate the role of NTs in a neuropathic pain.

Allodynia, Hyperalgesia, Neuropathic pain, Neurotrophins, Spinal nerve ligation