title: Behavior of neuropathic pain in mice following chronic constriction injury comparing silk and catgut ligatures.
abstract: BACKGROUND
  Neuropathic pain is defined as pain arising as a direct consequence of a lesion or disease affecting the somatosensory system and is common after surgery. Neuropathic pain can persist without an obvious injury. In this study we aim to validate a murine chronic constriction injury model as a model for neuropathic pain research and determine if silk or catgut ligatures induced most stable neuropathic pain behavior.
  
  
  METHODS
  In this study mice underwent chronic constriction or sham surgery. Mice were tested on cutaneous hyperalgesia with the cumulative reaction time in the acetone test, on allodynia with the cumulative reaction time and number of lifts in the cold plate test and the maximal force before withdrawal in von Frey test.
  
  
  RESULTS
  In the acetone test neuropathic pain was seen in CCI mice, but not in sham mice. Hyperalgesia was present postoperatively in CCI mice compared with preoperatively. In the cold plate test cumulative reaction time and number of lifts were higher in the ipsilateral hind paw than in the contralateral hind paw and sham mice. Postoperative measurements were higher than preoperatively. In the von Frey test the postoperative measurements were lower in the ipsilateral hind paw than preoperatively, while the contralateral hind paw showed an increase in maximal force before withdrawal. The contralateral hind paw showed more difference with sham mice than the ipsilateral hind paw. Silk ligatures showed more stable neuropathic pain behavior. In the acetone test, the cold plate test and the von Frey test the mice scored higher on neuropathic pain having silk ligatures, compared with catgut ligatures.
  
  
  CONCLUSIONS
  In this study we validated a murine CCI model for neuropathic pain behavior. In the murine CCI model it appears that silk ligatures demonstrate more stable neuropathic pain behaviors than catgut ligatures in de CCI model.
authors.affiliation: Department of Anesthesiology, Pain and Palliative Medicine, Radboud University Nijmegen Medical Centre (RUNMC), 6525 GA, Nijmegen, the Netherlands.
authors.forename: Selina
authors.initials: S
authors.lastname: van der Wal
authors.affiliation: Department of Anesthesiology, Pain and Palliative Medicine, Radboud University Nijmegen Medical Centre (RUNMC), 6525 GA, Nijmegen, the Netherlands.
authors.forename: Lisa
authors.initials: L
authors.lastname: Cornelissen
authors.affiliation: Department of Microbiology RUNMC, 6525 GA, Nijmegen, the Netherlands.
authors.forename: Marije
authors.initials: M
authors.lastname: Behet
authors.affiliation: Department of Anesthesiology, Pain and Palliative Medicine, Radboud University Nijmegen Medical Centre (RUNMC), 6525 GA, Nijmegen, the Netherlands.
authors.forename: Michiel
authors.initials: M
authors.lastname: Vaneker
authors.affiliation: Department of Anesthesiology, Pain and Palliative Medicine, Radboud University Nijmegen Medical Centre (RUNMC), 6525 GA, Nijmegen, the Netherlands.
authors.forename: Monique
authors.initials: M
authors.lastname: Steegers
authors.affiliation: Department of Anesthesiology, Pain and Palliative Medicine, Radboud University Nijmegen Medical Centre (RUNMC), 6525 GA, Nijmegen, the Netherlands.
authors.forename: Kris
authors.initials: K
authors.lastname: Vissers
keywords: Allodynia; Catgut; Hyperalgesia; Neuropathic pain; Silk