title: Contribution of capsaicin-sensitive primary afferents to mechanical hyperalgesia induced by ventral root transection in rats: the possible role of BDNF.
abstract: OBJECTIVE
  A recent study showed that brain-derived neurotrophic factor (BDNF) may play a role in the development of the neuropathic pain resulting from injury to motor efferent fibres, such as that in the ventral root transection (VRT) model. Capsaicin stimulation of afferent fibres was also shown to result in the release of BDNF into the spinal cord. Here, the effects of ablation of capsaicin-sensitive primary afferents (CSPAs) by local application of capsaicin on the sciatic nerve on VRT-induced mechanical hyperalgesia were observed.
  
  
  METHODS
  The paw withdrawal mechanical threshold (PWMT) was measured before and then 1 and 3 days and 1, 2, 3, 4 and 6 weeks after VRT.
  
  
  RESULTS
  The results showed that local application of capsaicin significantly inhibited the decrease in the PWMT induced by VRT, suggesting the inhibitory effect of locally delivered capsaicin. Furthermore, intrathecal administration of exogenous BDNF not only produced mechanical hyperalgesia but also significantly blocked the inhibitory effect of capsaicin.
  
  
  CONCLUSIONS
  Taken together, the results of this study suggest that CSPA fibres may contribute to mechanical hyperalgesia in the VRT model.
authors.affiliation: a Department of Neurology , General Hospital of Shen-Yang Military Area Command , Shen Yang 110840 , P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: a Department of Neurology , General Hospital of Shen-Yang Military Area Command , Shen Yang 110840 , P.R. China.
authors.forename: Jian-Xiu
authors.initials: JX
authors.lastname: Wang
authors.affiliation: a Department of Neurology , General Hospital of Shen-Yang Military Area Command , Shen Yang 110840 , P.R. China.
authors.forename: Zhong-He
authors.initials: ZH
authors.lastname: Zhou
authors.affiliation: a Department of Neurology , General Hospital of Shen-Yang Military Area Command , Shen Yang 110840 , P.R. China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Lu
authors.affiliation: a Department of Neurology , General Hospital of Shen-Yang Military Area Command , Shen Yang 110840 , P.R. China.
authors.forename: Xiao-Qiu
authors.initials: XQ
authors.lastname: Li
authors.affiliation: b Department of Medical Administration , General Hospital of Shen-Yang Military Area Command , Shen Yang 110840 , P.R. China.
authors.forename: Bao-Jun
authors.initials: BJ
authors.lastname: Liu
authors.affiliation: a Department of Neurology , General Hospital of Shen-Yang Military Area Command , Shen Yang 110840 , P.R. China.
authors.forename: Hui-Sheng
authors.initials: HS
authors.lastname: Chen
mesh_terms: D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism*; D002211:Capsaicin / Q000009:adverse effects*; D004195:Disease Models, Animal; D006930:Hyperalgesia / Q000139:chemically induced* / Q000473:pathology; D008297:Male; D009437:Neuralgia / Q000209:etiology*; D017288:Pain Threshold / Q000187:drug effects; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000473:pathology; D018689:Sensory System Agents / Q000009:adverse effects*; D013126:Spinal Nerve Roots / Q000293:injuries*; D018709:Statistics, Nonparametric; D014162:Transfection
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D018689:Sensory System Agents; D002211:Capsaicin
keywords: Brain-derived neurotrophic factor; Capsaicin-sensitive primary afferent; Mechanical hyperalgesia; Neuropathic pain