title: Monosodium iodoacetate-induced osteoarthritis produces pain-depressed wheel running in rats: implications for preclinical behavioral assessment of chronic pain.
abstract: Pain stimulates some behaviors (e.g., withdrawal responses) and depresses other behaviors (e.g., feeding and locomotion). We are developing methods for testing candidate analgesics using measurements of pain-depressed behaviors. Such assays may model important aspects of clinical pain and complement traditional procedures that measure pain-stimulated behaviors. The present study characterized the effects of a chronic pain manipulation (monosodium iodoacetate (MIA)-induced osteoarthritis) on wheel running in rats. Rats had 24 h voluntary access to running wheels. Duration of running wheel acquisition was manipulated such that rats had either 21 or 7 days of running wheel access prior to MIA administration. Wheel running was monitored for an additional 21 days following MIA administration. MIA produced concentration- and acquisition length-dependent decreases in wheel running. Parallel experiments demonstrated that MIA produced concentration-dependent tactile allodynia and shifts in hind limb weight bearing. MIA was differentially potent across assays with a potency rank: weight-bearing≥von Frey>running wheel. MIA produced greater depression of wheel running in rats with relatively high baseline running rates compared to rats with relatively low baseline running rates. The differential potency of MIA across assays and apparent rate-dependent effects in running wheels may impact our traditional interpretations of preclinical nociceptive and antinociceptive testing.
authors.affiliation: Department of Psychology, University of New England, Biddeford, ME 04005, United States. gstevenson@une.edu
authors.forename: Glenn W
authors.initials: GW
authors.lastname: Stevenson
authors.forename: Hannah
authors.initials: H
authors.lastname: Mercer
authors.forename: Jim
authors.initials: J
authors.lastname: Cormier
authors.forename: Catherine
authors.initials: C
authors.lastname: Dunbar
authors.forename: Laura
authors.initials: L
authors.lastname: Benoit
authors.forename: Chloe
authors.initials: C
authors.lastname: Adams
authors.forename: Justin
authors.initials: J
authors.lastname: Jezierski
authors.forename: Amy
authors.initials: A
authors.lastname: Luginbuhl
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Bilsky
mesh_terms: D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D002908:Chronic Disease; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D006614:Hindlimb; D007461:Iodoacetates / Q000633:toxicity*; D008297:Male; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology*; D010003:Osteoarthritis / Q000139:chemically induced* / Q000503:physiopathology*; D010146:Pain / Q000188:drug therapy / Q000503:physiopathology*; D010147:Pain Measurement / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D016474:Weight-Bearing
chemical_list: D000700:Analgesics; D007461:Iodoacetates