Evaluation of a Postoperative Pain-Like State on Motivated Behavior in Rats: Effects of Plantar Incision on Progressive-Ratio Food-Maintained Responding.
There has been recent interest in characterizing the effects of pain-like states on motivated behaviors in order to quantify how pain modulates goal-directed behavior and the persistence of that behavior. The current set of experiments assessed the effects of an incisional postoperative pain manipulation on food-maintained responding under a progressive-ratio (PR) operant schedule. Independent variables included injury state (plantar incision or anesthesia control) and reinforcer type (grain pellet or sugar pellet); dependent variables were tactile sensory thresholds and response breakpoint. Once responding stabilized on the PR schedule, separate groups of rats received a single ventral hind paw incision or anesthesia (control condition). Incision significantly reduced breakpoints in rats responding for grain, but not sugar. In rats responding for sugar, tactile hypersensitivity recovered within 24 hr, indicating a faster recovery of incision-induced tactile hypersensitivity compared to rats responding for grain, which demonstrated recovery at PD2. The NSAID analgesic, diclofenac (5.6 mg/kg) completely restored incision-depressed PR operant responding and tactile sensitivity at 3 hr following incision. The PR schedule differentiated between sucrose and grain, suggesting that relative reinforcing efficacy may be an important determinant in detecting pain-induced changes in motivated behavior.
Department of Psychology, University of New England, Biddeford, ME, 04005, USA.
Emily
E
Warner
Department of Psychology, University of New England, Biddeford, ME, 04005, USA.
Rebecca
R
Krivitsky
Department of Psychology, University of New England, Biddeford, ME, 04005, USA.
Katherine
K
Cone
Department of Psychology, University of New England, Biddeford, ME, 04005, USA.
Phillip
P
Atherton
Department of Psychology, University of New England, Biddeford, ME, 04005, USA.
Travis
T
Pitre
Department of Psychology, University of New England, Biddeford, ME, 04005, USA.
Janell
J
Lanpher
Department of Biomedical Sciences, University of New England College of Osteopathic Medicine, Biddeford, ME, 04005, USA.
Denise
D
Giuvelis
Department of Biomedical Sciences, University of New England College of Osteopathic Medicine, Biddeford, ME, 04005, USA.
Ivy
I
Bergquist
Department of Biomedical Sciences, University of New England College of Osteopathic Medicine, Biddeford, ME, 04005, USA.|Center for Excellence in the Neurosciences, University of New England, ME, 04005, USA.
Tamara
T
King
Department of Biomedical Sciences, University of New England College of Osteopathic Medicine, Biddeford, ME, 04005, USA.|Center for Excellence in the Neurosciences, University of New England, ME, 04005, USA.
Edward J
EJ
Bilsky
Department of Psychology, University of New England, Biddeford, ME, 04005, USA.|Center for Excellence in the Neurosciences, University of New England, ME, 04005, USA.
Glenn W
GW
Stevenson
D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D003216:Conditioning, Operant / Q000187:drug effects / Q000502:physiology*; D004008:Diclofenac / Q000494:pharmacology; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology* / Q000523:psychology; D006614:Hindlimb / Q000601:surgery; D008297:Male; D009042:Motivation; D059225:Nociception / Q000187:drug effects / Q000502:physiology; D010149:Postoperative Pain / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012055:Reinforcement Schedule
D000700:Analgesics; D004008:Diclofenac
nociception; operant conditioning; pain-depressed behavior; postoperative incisional pain; preclinical pain assay; progressive ratio schedules