title: Characterization of the Affective Component of Acute Postoperative Pain Associated with a Novel Rat Model of Inguinal Hernia Repair Pain.
abstract: OBJECTIVE
  Acute postoperative pain remains a significant healthcare issue. Historically, the assessment of postoperative pain in rodents has relied on evoked withdrawal or reflexive measures. Using a recently developed, anatomically relevant rat model of acute postoperative pain (J Pain, 16, 2015, 421), the present experiments sought to investigate the affective component of acute postoperative pain associated with inguinal hernia repair.
  
  
  METHODS
  Male Lister hooded rats underwent surgery to model Lichtenstein inguinal hernia repair (without hernia induction), or a sham procedure. Postsurgical characterization involved a modified place escape/avoidance paradigm (mPEAP), as well as home cage and open field locomotor activity monitoring. In pharmacological validation studies, rats received either morphine or carprofen prior to mPEAP testing.
  
  
  RESULTS
  Surgery was associated with a significantly increased proportion of the trial duration in the light compartment of the mPEAP arena, in avoidance of the noxious stimulus, compared with sham animals. When retested in the mPEAP at day 7 postsurgery, there was no difference between sham and surgery animals for time spent in either compartment, but surgery animals displayed a persistent increase in the percentage response to noxious stimulation. Morphine and carprofen treatment in surgery animals reduced escape/avoidance behavior at discrete time points over the trial. Surgery-induced reductions in home cage and open field locomotor activity were also observed.
  
  
  CONCLUSIONS
  The present studies report for the first time the characterization of the affective component of acute postoperative pain using the mPEAP in a rodent model, which may facilitate development of improved understanding and treatment of postoperative pain.
authors.affiliation: Pharmacology and Therapeutics, School of Medicine, National University of Ireland, Galway, Ireland.|Physiology, School of Medicine, National University of Ireland, Galway, Ireland.|Galway Neuroscience Centre and Centre for Pain Research, NCBES, National University of Ireland, Galway, Ireland.
authors.forename: Dara
authors.initials: D
authors.lastname: Bree
authors.affiliation: Pharmacology and Therapeutics, School of Medicine, National University of Ireland, Galway, Ireland.|Physiology, School of Medicine, National University of Ireland, Galway, Ireland.|Galway Neuroscience Centre and Centre for Pain Research, NCBES, National University of Ireland, Galway, Ireland.|Research and Development, Covidien, North Haven, CT, USA.
authors.forename: Orla
authors.initials: O
authors.lastname: Moriarty
authors.affiliation: Research and Development, Covidien, North Haven, CT, USA.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Broom
authors.affiliation: Pharmacology and Therapeutics, School of Medicine, National University of Ireland, Galway, Ireland.|Galway Neuroscience Centre and Centre for Pain Research, NCBES, National University of Ireland, Galway, Ireland.
authors.forename: John P
authors.initials: JP
authors.lastname: Kelly
authors.affiliation: Physiology, School of Medicine, National University of Ireland, Galway, Ireland.|Galway Neuroscience Centre and Centre for Pain Research, NCBES, National University of Ireland, Galway, Ireland.
authors.forename: Michelle
authors.initials: M
authors.lastname: Roche
authors.affiliation: Pharmacology and Therapeutics, School of Medicine, National University of Ireland, Galway, Ireland.|Galway Neuroscience Centre and Centre for Pain Research, NCBES, National University of Ireland, Galway, Ireland.
authors.forename: David P
authors.initials: DP
authors.lastname: Finn
mesh_terms: D059787:Acute Pain / Q000188:drug therapy / Q000209:etiology / Q000523:psychology*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology / Q000627:therapeutic use; D002227:Carbazoles / Q000494:pharmacology / Q000627:therapeutic use; D004195:Disease Models, Animal; D006552:Hernia, Inguinal / Q000188:drug therapy / Q000523:psychology* / Q000601:surgery*; D008297:Male; D010147:Pain Measurement / Q000187:drug effects / Q000379:methods / Q000523:psychology*; D010149:Postoperative Pain / Q000188:drug therapy / Q000209:etiology / Q000523:psychology*; D051381:Rats
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D002227:Carbazoles; C007005:carprofen
keywords: Affect; Carprofen; Hernia repair; Locomotor activity; Morphine; PEAP; Postsurgical pain