title: Comparison of CatWalk analysis and von Frey testing for pain assessment in a rat model of nerve crush plus inflammation.
abstract: METHODS
  Assessment of pain-related behavior and immunohistology of the dorsal root ganglion in a rat model.
  
  
  OBJECTIVE
  To investigate pain-related behavior in a rat model of nerve crush plus inflammation using the CatWalk system.
  
  
  BACKGROUND
  A definitive method for evaluating animal models of lumbar disease has not been established. Von Frey testing has often been used in this type of study, but the reliability remains in question. The CatWalk system is a computer-assisted apparatus for analyzing gait that provides an automated way to assess gait function during pain. However, there have been few reports using this system for models of lumbar disease.
  
  
  METHODS
  Fourteen rats were divided into 2 groups: a treatment group and a sham group. For the treatment group, nucleus pulposus was applied to the sciatic nerve and the sciatic nerve was pinched. Two different methods for assessment of pain-related behavior, von Frey testing and CatWalk analysis, were used before surgery and at 4 and 7 days after surgery. Immunohistochemistry was used to examine calcitonin gene-related peptide expression in L4 to L6 dorsal root ganglia.
  
  
  RESULTS
  No significant differences were found between the treatment and sham control groups using von Frey testing. However, significant differences in 4 parameters were found between the 2 groups using the CatWalk system (P < 0.05). The proportion of calcitonin gene-related peptide-immunoreactive neurons was higher in the treatment group than in the control group (P < 0.05).
  
  
  CONCLUSIONS
  Our results demonstrate that the CatWalk system is useful for the measurement of pain-related behavioral change in our rat model in which nociception was indicated at a cellular level. Although further studies are needed, we think that this system is a valid alternative method for the evaluation of models of lumbar disease in rodents.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Inohana, Chuo-ku, Chiba, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Sakuma
authors.forename: Hiroto
authors.initials: H
authors.lastname: Kamoda
authors.forename: Masayuki
authors.initials: M
authors.lastname: Miyagi
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Gen
authors.initials: G
authors.lastname: Arai
authors.forename: Yawara
authors.initials: Y
authors.lastname: Eguchi
authors.forename: Miyako
authors.initials: M
authors.lastname: Suzuki
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Oikawa
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sakuma
authors.forename: Go
authors.initials: G
authors.lastname: Kubota
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Inage
authors.forename: Takeshi
authors.initials: T
authors.lastname: Saino
authors.forename: Sumihisa
authors.initials: S
authors.lastname: Orita
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Yamauchi
authors.forename: Gen
authors.initials: G
authors.lastname: Inoue
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Takahashi
authors.forename: Seiji
authors.initials: S
authors.lastname: Ohtori
mesh_terms: D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D004195:Disease Models, Animal; D005684:Gait / Q000502:physiology; D005727:Ganglia, Spinal / Q000378:metabolism / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000294:innervation; D009409:Nerve Crush; D010146:Pain / Q000175:diagnosis / Q000378:metabolism / Q000503:physiopathology*; D010147:Pain Measurement / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012584:Sciatic Nerve / Q000503:physiopathology* / Q000601:surgery; D012680:Sensitivity and Specificity
chemical_list: D015740:Calcitonin Gene-Related Peptide