2017 Volume 32 Issue 3 Pages 212-215
Background: Brain–derived neurotrophic factor (BDNF) may play an important neuromodulatory role in spinal cord. The aim of this study was assessed a relationship between pain–related behavior, expression of BDNF and p38 induced by nucleus pulposus (NP) applied to nerve roots in rats.
Methods: Adult female Sprague–Dawley rats were used. NP was applied to the left L5 DRG of rats in the NP group. In the sham group, the same procedure was performed without NP application on the DRG. The mechanical withdrawal threshold was investigated using von Frey hairs. And immunohistochemical analyses of phosphorylated p38 (p38) and BDNF in the spinal cord were observed to colocalize with neuron (NeuN) and microglia (OX42). The numbers of p38 and BDNF immune–reactive (IR) cells in the dorsal horn were counted.
Results: The mechanical withdrawal threshold in the NP group was significantly decreased for 35 days compared with that in the sham group. Both p38 and BDNF positive cells were localized with microglia and neurons in spinal cord. In the NP group, the expression of p38–IR and BDNF–IR cells increased from day 2 to 21 compared with the sham group.
Conclusions: According to the results of this study, the mechanical threshold was reduced from 2 days after surgery, and BDNF and p38 were expressed in both activated microglia and neurons in spinal cord. BDNF and p38 expression might be the important role to induce neuropathic pain.
