title: Maxillary nerve compression in cynomolgus monkey Macaca fascicularis: altered somatic sensation and peripheral nerve firing.
abstract: BACKGROUND
  Trigeminal nerve is a major source of the sensory input of the face, and trigeminal neuropathology models have been reported in rodents with injury to branches of the maxillary or mandibular division of the trigeminal nerve. Non-human primates are neuroanatomically more closely related to human than rodents; however, nerve injury studies in non-human primates are limited.
  
  
  RESULTS
  We describe here a nerve injury model of maxillary nerve compression (MNC) in the cynomolgus macaque monkey, Macaca fascicularis, and the initial characterization of the consequences of damage to this trigeminal nerve branch. The nerve injury from the compression appeared to be mild, as we did not observe overt changes in home-cage behavior in the monkeys. When mechanical stimulation was applied to the facial area, monkeys with MNC displayed increased mechanical sensitivity, as the avoidance response scores were lower than those from the control animals. Such a change in mechanical sensitivity appeared to be somewhat bilateral, as the contralateral side also showed increased mechanical sensitivity, although the change on the ipsilateral side was more robust. Multiple-unit recording of the maxillary nerve showed a general pattern of increasing responsiveness to escalating force in mechanical stimulation on the contralateral side. Ipsilateral side of the maxillary nerve showed a lack of responsiveness to escalating force in mechanical stimulation, possibly reflecting a maximum stimulation threshold effect from sensitized nerve due to MNC injury.
  
  
  CONCLUSIONS
  These results suggest that MNC may produce increased sensitivity of the ipsilateral maxillary nerve, and that this model may serve as a non-human primate model to evaluate the effect of injury to trigeminal nerve branches.
authors.affiliation: Shanghai University of Traditional Chinese Medicine, and ShanghaiBio Corporation, Shanghai, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Guo
authors.forename: Xiyao
authors.initials: X
authors.lastname: Gu
authors.forename: Jun
authors.initials: J
authors.lastname: Zhao
authors.forename: Guoping
authors.initials: G
authors.lastname: Zhao
authors.forename: Meilei
authors.initials: M
authors.lastname: Jin
authors.forename: Hong
authors.initials: H
authors.lastname: Zou
authors.forename: Yuqiu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zhiqi
authors.initials: Z
authors.lastname: Zhao
authors.forename: Gang Jason
authors.initials: GJ
authors.lastname: Jin
authors.forename: Lei
authors.initials: L
authors.lastname: Yu
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D004195:Disease Models, Animal; D005145:Face / Q000503:physiopathology; D008252:Macaca fascicularis; D008297:Male; D008442:Maxillary Nerve / Q000293:injuries* / Q000503:physiopathology*; D009408:Nerve Compression Syndromes / Q000503:physiopathology*; D010812:Physical Stimulation / Q000379:methods; D012677:Sensation / Q000502:physiology*