title: Orofacial neuropathic pain mouse model induced by Trigeminal Inflammatory Compression (TIC) of the infraorbital nerve.
abstract: BACKGROUND
  Trigeminal neuropathic pain attacks can be excruciating for patients, even after being lightly touched. Although there are rodent trigeminal nerve research models to study orofacial pain, few models have been applied to studies in mice. A mouse trigeminal inflammatory compression (TIC) model is introduced here which successfully and reliably promotes vibrissal whisker pad hypersensitivity.
  
  
  RESULTS
  The chronic orofacial neuropathic pain model is induced after surgical placement of chromic gut suture in the infraorbital nerve fissure in the maxillary bone. Slight compression and chemical effects of the chromic gut suture on the portion of the infraorbital nerve contacted cause mild nerve trauma. Nerve edema is observed in the contacting infraorbital nerve bundle as well as macrophage infiltration in the trigeminal ganglia. Centrally in the spinal trigeminal nucleus, increased immunoreactivity for an activated microglial marker is evident (OX42, postoperative day 70). Mechanical thresholds of the affected whisker pad are significantly decreased on day 3 after chromic gut suture placement, persisting at least 10 weeks. The mechanical allodynia is reversed by suppression of microglial activation. Cold allodynia was detected at 4 weeks.
  
  
  CONCLUSIONS
  A simple, effective, and reproducible chronic mouse model mimicking clinical orofacial neuropathic pain (Type 2) is induced by placing chromic gut suture between the infraorbital nerve and the maxillary bone. The method produces mild inflammatory compression with significant continuous mechanical allodynia persisting at least 10 weeks and cold allodynia measureable at 4 weeks.
authors.affiliation: Department of Physiology MS-508, College of Medicine, University of Kentucky, Lexington, KY 40536-0298, USA.
authors.forename: Fei
authors.initials: F
authors.lastname: Ma
authors.forename: Liping
authors.initials: L
authors.lastname: Zhang
authors.forename: Danielle
authors.initials: D
authors.lastname: Lyons
authors.forename: Karin N
authors.initials: KN
authors.lastname: Westlund
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004195:Disease Models, Animal; D005157:Facial Pain / Q000150:complications / Q000473:pathology*; D006930:Hyperalgesia / Q000150:complications / Q000473:pathology; D007093:Imidazoles / Q000494:pharmacology; D007249:Inflammation / Q000150:complications / Q000473:pathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000187:drug effects / Q000473:pathology; D008911:Minocycline / Q000494:pharmacology; D009408:Nerve Compression Syndromes / Q000150:complications / Q000473:pathology*; D009437:Neuralgia / Q000150:complications / Q000473:pathology*; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D009915:Orbit / Q000187:drug effects / Q000294:innervation* / Q000473:pathology*; D058920:Purinergic P2X Receptor Antagonists / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D013777:Tetrazoles / Q000494:pharmacology; D012668:Trigeminal Ganglion / Q000187:drug effects / Q000473:pathology; D014276:Trigeminal Nerve / Q000187:drug effects / Q000473:pathology*; D014277:Trigeminal Neuralgia / Q000150:complications / Q000473:pathology; D014279:Trigeminal Nucleus, Spinal / Q000187:drug effects / Q000473:pathology; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: C523668:3-(5-(2,3-dichlorophenyl)-1H-tetrazol-1-yl)methylpyridine; D007093:Imidazoles; D058920:Purinergic P2X Receptor Antagonists; D011725:Pyridines; D013777:Tetrazoles; D048051:p38 Mitogen-Activated Protein Kinases; D008911:Minocycline; C093642:SB 203580