title: Rat Model of Trigeminal Neuralgia Using Cobra Venom Mimics the Electron Microscopy, Behavioral, and Anticonvulsant Drug Responses Seen in Patients.
abstract: BACKGROUND
  A new animal model of trigeminal neuralgia produced by injecting cobra venom into the infraorbital nerve (ION) trunk in rats had been developed. We tested and extended the model by observing the ultrastructural alterations of neurons and ameliorative effect of pregabalin in cobra venom-induced pain behaviors of rats.
  
  
  OBJECTIVE
  The goal of this study was to prove the feasibility of the cobra venom-induced model of trigeminal neuralgia and to demonstrate the demyelination change of ION and medulla oblongata is the major pathological change of trigeminal neuralgia.
  
  
  METHODS
  An experimental study.
  
  
  METHODS
  Department of Anesthesiology, Pain Medicine, and Critical Care Medicine, Aviation General Hospital of China Medical University.
  
  
  METHODS
  Experiments were carried out on male Sprague-Dawley rats. Video recordings were taken after the cobra venom injection and pregabalin administration. Ultrastructural alterations of ION and medulla oblongata were observed at the electron microscopic level. We also observed alteration in pain behaviors by analysis of video recordings.
  
  
  RESULTS
  Compared to the preoperative and sham-operated group rats, experimental group rats exhibited significant changes in exploratory, resting, face-grooming, and head-shake behaviors on 3, 7, 14 days after operation (P < 0.01). The demyelination changes of ION and medulla oblongata were evident after administration of cobra venom to the ION. Compared to the pre-treated (no pregabalin administration) and control group rats, pregabalin group rats showed profound changes in exploratory, resting, face-grooming, and head-shake behaviors throughout the 14 day study period after treatment with drugs (P < 0.01).
  
  
  CONCLUSIONS
  Ultrastructural alterations of ION and medulla oblongata were not examined after the treatment with pregabalin.
  
  
  CONCLUSIONS
  Video recordings of free behaviors and pregabalin application prove the feasibility of the rat model of trigeminal neuralgia. The results of electron micrographs are consistent with a previous study in humans showing that the demyelination change of axons is the major pathological change of trigeminal neuralgia. The central demyelination alterations may explain why the mechanical threshold was found to be decreased on the non-operated side of experimental animals.
authors.forename: Qian-Qian
authors.initials: QQ
authors.lastname: Zhao
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Qian
authors.forename: Jian-Xiong
authors.initials: JX
authors.lastname: An
authors.forename: Cai-Cai
authors.initials: CC
authors.lastname: Liu
authors.forename: Qi-Wu
authors.initials: QW
authors.lastname: Fang
authors.affiliation: Department of Anesthesiology, Pain Medicine & Critical Care Medicine, Aviation General Hospital of China Medical University & Beijing Institute of Translational Medicine, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, Pain Medicine & Critical Care Medicine, Aviation General Hospital of China Medical University & Beijing Institute of Translational Medicine, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yi-De
authors.initials: YD
authors.lastname: Jiang
authors.forename: Doris K
authors.initials: DK
authors.lastname: Cope
authors.forename: John P
authors.initials: JP
authors.lastname: Williams
mesh_terms: D000700:Analgesics / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology / Q000627:therapeutic use*; D004195:Disease Models, Animal; D004546:Elapid Venoms / Q000633:toxicity*; D005106:Exploratory Behavior / Q000187:drug effects*; D006801:Humans; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects / Q000473:pathology / Q000648:ultrastructure; D008854:Microscopy, Electron / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D016896:Treatment Outcome; D014277:Trigeminal Neuralgia / Q000139:chemically induced* / Q000188:drug therapy / Q000473:pathology*
chemical_list: D000700:Analgesics; D000927:Anticonvulsants; D004546:Elapid Venoms