title: Rotterdam Advanced Multiple Plate: a novel method to measure cold hyperalgesia and allodynia in freely behaving rodents.
abstract: BACKGROUND
  To investigate the pathophysiology of temperature hypersensitivity in neuropathic pain rodent models, it is essential to be able to quantify the phenotype as objective as possible. Current temperature sensitivity measuring paradigms are performed during exposure to external factors, i.e. light, sound and smell, which modulate behavior significantly. In addition the present outcome measure for temperature hypersensitivity in rodents is the examination of the hind paw lift upon exposure to a certain temperature, which reflects more a reflex-flexion than an experience of pain.
  
  
  METHODS
  Therefore the Rotterdam Advanced Multiple Plate (RAMP) was developed to assess cold hyperalgesia and allodynia objectively in freely behaving neuropathic pain rats, which measures the avoidance for certain temperatures and monitoring the location of the rat with an infrared camera while excluding external environmental influences such as light and sound.
  
  
  RESULTS
  Compared to sham rats, the spared nerve injury (SNI) rats demonstrated a higher preference for the comfortable plate (27 °C) when the other three plates were set at 5 °C, 14 °C, 17 °C and 19 °C. We were unable to detect heat hyperalgesia and allodynia with the RAMP.
  
  
  CONCLUSIONS
  The paw withdrawal method displays similar results during cold hypersensitivity measurements as observed with the RAMP. The SNI group did display heat hypersensitivity during the paw withdrawal test.
  
  
  CONCLUSIONS
  The results indicate that the RAMP is able to quantify cold hyperalgesia and allodynia in neuropathic pain rats while resolves some of the problems of conventional temperature sensitivity measuring paradigms in rodents.
authors.affiliation: Department of Neuroscience, Erasmus MC, University Medical Center Rotterdam, The Netherlands; Department of Plastic, Reconstructive and Hand Surgery, Erasmus MC, University Medical Center Rotterdam, The Netherlands. Electronic address: l.duraku@erasmusmc.nl.
authors.forename: Liron S
authors.initials: LS
authors.lastname: Duraku
authors.affiliation: Pain Treatment Centre, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands. Electronic address: s.niehof@erasumsmc.nl.
authors.forename: Sjoerd P
authors.initials: SP
authors.lastname: Niehof
authors.affiliation: Department of Plastic, Reconstructive and Hand Surgery, Erasmus MC, University Medical Center Rotterdam, The Netherlands. Electronic address: yesim.misirli@gmail.com.
authors.forename: Yesim
authors.initials: Y
authors.lastname: Misirli
authors.affiliation: Department of Neuroscience, Erasmus MC, University Medical Center Rotterdam, The Netherlands. Electronic address: mar_en_co@ziggo.nl.
authors.forename: Marco
authors.initials: M
authors.lastname: Everaers
authors.affiliation: Department of Plastic, Reconstructive and Hand Surgery, Erasmus MC, University Medical Center Rotterdam, The Netherlands. Electronic address: sieske_h2@hotmail.com.
authors.forename: Sieske
authors.initials: S
authors.lastname: Hoendervangers
authors.affiliation: Department of Neuroscience, Erasmus MC, University Medical Center Rotterdam, The Netherlands. Electronic address: j.holstege@erasmusmc.nl.
authors.forename: Joan
authors.initials: J
authors.lastname: Holstege
authors.affiliation: Department of Neuroscience, Erasmus MC, University Medical Center Rotterdam, The Netherlands. Electronic address: h.boele@erasmusmc.nl.
authors.forename: Henk-Jan J
authors.initials: HJ
authors.lastname: Boele
authors.affiliation: Department of Neuroscience, Erasmus MC, University Medical Center Rotterdam, The Netherlands. Electronic address: s.koekkoek@erasmusmc.nl.
authors.forename: Sebastiaan K E
authors.initials: SKE
authors.lastname: Koekkoek
authors.affiliation: Department of Plastic, Reconstructive and Hand Surgery, Erasmus MC, University Medical Center Rotterdam, The Netherlands. Electronic address: e.smits@erasmusmc.nl.
authors.forename: Ernst S
authors.initials: ES
authors.lastname: Smits
authors.affiliation: Department of Plastic, Reconstructive and Hand Surgery, Erasmus MC, University Medical Center Rotterdam, The Netherlands; Department of Rehabilitation Medicine, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands. Electronic address: r.selles@erasmusmc.nl.
authors.forename: Ruud W
authors.initials: RW
authors.lastname: Selles
authors.affiliation: Department of Plastic, Reconstructive and Hand Surgery, Erasmus MC, University Medical Center Rotterdam, The Netherlands. Electronic address: e.walbeehm@erasmusmc.nl.
authors.forename: Erik T
authors.initials: ET
authors.lastname: Walbeehm
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D003080:Cold Temperature / Q000009:adverse effects*; D004195:Disease Models, Animal; D006930:Hyperalgesia / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D009437:Neuralgia / Q000150:complications; D010147:Pain Measurement / Q000295:instrumentation / Q000379:methods*; D017288:Pain Threshold / Q000502:physiology*; D011601:Psychophysics; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D013997:Time Factors; D014851:Wakefulness
keywords: Allodynia; Cold; Heat; Hyperalgesia; Neuropathic pain; Rat; SNI