BDNF Increases The Expression Of NR2B In The Spinal Dorsal With CCI Rats Through MTOR Singal Pathway Which Is Involved In The Maintence Of Neuropathic Pain

ObjectiveBrain-derived neurotrophic factor play an important role in neuropathic pain, however the mechanism of BDNF involved in neuropathic pain is unclear until now. It was investigated that endogenous BDNF involved in neuropathic pain Whether related NR2B expression augment through mTOR signaling pathways in spinal dorsal horn of CCI rats.Method35healthy Male Sprague-Dawley rats were randomly divided into seven groups(n=5):①Normal control group:no treated.②The CCI model group:separating the left sciatic nerve and ligation.③The sham operation group:separating the left sciatic nerve without ligation.④Anti-BDNF antibody group:intrathecal administration of anti-brain derived neurotrophic factor antibody30minutes before CCI surgery, once a day, until to the seventh day.⑤Saline solvent group:intrathecal administration of saline30minutes before CCI surgery, once a day, until to the seventh day.⑥Rapamycin group:intrathecal administration of rapamycin30minutes before CCI surgery, once a day, until to the seventh day.⑦MSO group:intrathecal administration of DMSO30minutes before CCI surgery, once a day, until to the seventh day. Establishment of the CCI model three days after the success of intrathecal catheteritation. Taking the lumbar spinal cord specimens in the eighth day postoperative CCI for morphological observation and molecular analysis.Result1. Behavioral results:The basal pain threshold PWMT and PWTL in each experimental group were no significant differences (P>0.05). PWMT and PWTL were no significant difference at all time points between normal control group and sham operation group (P>0.05). In the CCI group, saline solvent group and DMSO group, PWMT and PWTL began to decline one day after surgery (P<0.05), and until to the seventh day. Compared with the CCI group, PWMT and PWTL obviously increased at all the point after CCI survey in anti-BDNF antibody group and rapamycin group (P<0.05).2. Immunohistochemical results of p-mTOR protein and NR2B protein:p-mTOR protein and NR2B protein expression mainly located in the spinal superficial dorsal horn. There was no significantly difference between the normal control group and sham operation group (P>0.05). compared with normal control group, CCI group, saline solvent group and DMSO group were obviously increased (P<0.05). compared with CCI group, anti-BDNF antibody group and rapamycin group were obviously decreased (P<0.05).3. Western blot results of p-mTOR protein and NR2B protein:There was no significant difference between the normal control group and sham group (P>0.05). compared with normal control group, CCI group, saline solvent group and DMSO group were obviously increased (P<0.05). compared with CCI group, anti-BDNF antibody group and rapamycin group were obviously decreased (P<0.05).Conclusion1. Endogenous BDNF involved in the generation and maintenance of neuropathic pain, anti-BDNF antibody can alleviate the pain of CCI rats;2. Endogenous BDNF involved in the maintenance of neuropathic pain related with upregulation of NR2B expression in spinal dorsal horn through mTOR signal pathway.