title: Mechanical Conflict System: A Novel Operant Method for the Assessment of Nociceptive Behavior.
abstract: A new operant test for preclinical pain research, termed the Mechanical Conflict System (MCS), is presented. Rats were given a choice either to remain in a brightly lit compartment or to escape to a dark compartment by crossing an array of height-adjustable nociceptive probes. Latency to escape the light compartment was evaluated with varying probe heights (0, .5, 1, 2, 3, and 4 mm above compartment floor) in rats with neuropathic pain induced by constriction nerve injury (CCI) and in naive control rats. Escape responses in CCI rats were assessed following intraperitoneal administration of pregabalin (10 and 30 mg/kg), morphine (2.5 and 5 mg/kg), and the tachykinin NK1 receptor antagonist, RP 67580 (1 and 10 mg/kg). Results indicate that escape latency increased as a function of probe height in both naive and CCI rats. Pregabalin (10 and 30 mg/kg) and morphine (5 mg/kg), but not RP 67580, decreased latency to escape in CCI rats suggesting an antinociceptive effect. In contrast, morphine (10 mg/kg) but not pregabalin (30 mg/kg) increased escape latency in naive rats suggesting a possible anxiolytic action of morphine in response to light-induced fear. No order effects following multiple test sessions were observed. We conclude that the MCS is a valid method to assess behavioral signs of affective pain in rodents.
authors.affiliation: Department of Anesthesiology, Chronic Pain and Fatigue Research Center, University of Michigan, Ann Arbor, Michigan, United States of America.|Department of Internal Medicine, Division of Rheumatology, University of Michigan, Ann Arbor, Michigan, United States of America.|Neurology Service, Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan, United States of America.
authors.forename: Steven E
authors.initials: SE
authors.lastname: Harte
authors.affiliation: Department of Neurology, University of Michigan, Ann Arbor, Michigan, United States of America.|Neurology Service, Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan, United States of America.
authors.forename: Jessica B
authors.initials: JB
authors.lastname: Meyers
authors.affiliation: Department of Physiology, University of Kentucky, Lexington, Kentucky, United States of America.
authors.forename: Renee R
authors.initials: RR
authors.lastname: Donahue
authors.affiliation: Department of Physiology, University of Kentucky, Lexington, Kentucky, United States of America.|Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, United States of America.
authors.forename: Bradley K
authors.initials: BK
authors.lastname: Taylor
authors.affiliation: Department of Neurology, University of Michigan, Ann Arbor, Michigan, United States of America.|Neurology Service, Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan, United States of America.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Morrow
mesh_terms: D000700:Analgesics / Q000008:administration & dosage / Q000627:therapeutic use; D000818:Animals; D014151:Anti-Anxiety Agents / Q000008:administration & dosage / Q000627:therapeutic use; D001362:Avoidance Learning / Q000502:physiology*; D002755:Choice Behavior; D003216:Conditioning, Operant / Q000502:physiology; D003220:Conflict, Psychological; D003624:Darkness; D004305:Dose-Response Relationship, Drug; D004924:Escape Reaction / Q000502:physiology*; D005010:Ethology / Q000295:instrumentation*; D005239:Fear; D018409:Foot Injuries / Q000503:physiopathology* / Q000523:psychology; D006930:Hyperalgesia / Q000209:etiology / Q000503:physiopathology* / Q000523:psychology; D007274:Injections, Intraperitoneal; D054833:Isoindoles / Q000008:administration & dosage / Q000627:therapeutic use; D008026:Ligation; D008027:Light / Q000009:adverse effects; D008297:Male; D009020:Morphine / Q000008:administration & dosage / Q000627:therapeutic use; D009437:Neuralgia / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology; D064729:Neurokinin-1 Receptor Antagonists / Q000008:administration & dosage / Q000627:therapeutic use; D059226:Nociceptive Pain / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology; D000069583:Pregabalin / Q000008:administration & dosage / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects; D012584:Sciatic Nerve / Q000293:injuries / Q000503:physiopathology
chemical_list: D000700:Analgesics; D014151:Anti-Anxiety Agents; D054833:Isoindoles; D064729:Neurokinin-1 Receptor Antagonists; C071693:7,7-diphenyl-2-(1-imino-2-(2-methoxyphenyl)ethyl)perhydroisoindol-4-one; D000069583:Pregabalin; D009020:Morphine