title: Inhibitory effects of heterotopic noxious counter-stimulation on perception and brain activity related to Aβ-fibre activation.
abstract: Heterotopic noxious counter-stimulation (HNCS) inhibits pain and pain processes through cerebral and cerebrospinal mechanisms. However, it is unclear whether HNCS inhibits non-nociceptive processes, which needs to be clarified for a better understanding of HNCS analgesia. The aim of this study was to examine the effects of HNCS on perception and scalp somatosensory evoked potentials (SEPs). Seventeen healthy volunteers participated in two counter-balanced sessions, including non-nociceptive (selective Aβ-fibre activation) or nociceptive electrical stimulation, combined with HNCS. HNCS was produced by a 20-min cold pressor test (left hand) adjusted individually to produce moderate pain (mean ± SEM: 42.5 ± 5.3 on a 0-100 scale, where 0 is no pain and 100 the worst pain imaginable). Non-nociceptive electrical stimulation was adjusted individually at 80% of pain threshold and produced a tactile sensation in every subject. Nociceptive electrical stimulation was adjusted individually at 120% of RIII-reflex threshold and produced moderate pain (45.3 ± 4.5). Shock sensation was significantly decreased by HNCS compared with baseline for non-nociceptive (P < 0.001) and nociceptive (P < 0.001) stimulation. SEP peak-to-peak amplitude at Cz was significantly decreased by HNCS for non-nociceptive (P < 0.01) and nociceptive (P < 0.05) stimulation. These results indicate that perception and brain activity related to Aβ-fibre activation are inhibited by HNCS. The mechanisms of this effect remain to be investigated to clarify whether it involves inhibition of spinal wide-dynamic-range neurons by diffuse noxious inhibitory controls, supraspinal processes or both.
authors.affiliation: Department of Chiropractic, Université du Québec à Trois-Rivières, 3351 Boul. des Forges, C.P. 500, Trois-Rivières, QC, G9A 5H7, Canada.|Groupe de Recherche en Cognition, Neuroscience, Affect et Comportement (CogNAC), Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.
authors.forename: Nabi
authors.initials: N
authors.lastname: Rustamov
authors.affiliation: Department of Chiropractic, Université du Québec à Trois-Rivières, 3351 Boul. des Forges, C.P. 500, Trois-Rivières, QC, G9A 5H7, Canada.|Groupe de Recherche en Cognition, Neuroscience, Affect et Comportement (CogNAC), Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.
authors.forename: Jessica
authors.initials: J
authors.lastname: Tessier
authors.affiliation: Department of Chiropractic, Université du Québec à Trois-Rivières, 3351 Boul. des Forges, C.P. 500, Trois-Rivières, QC, G9A 5H7, Canada.|Groupe de Recherche en Cognition, Neuroscience, Affect et Comportement (CogNAC), Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Provencher
authors.affiliation: Department of Otolaryngology Head & Neck Surgery, McGill University, Montreal, QC, Canada.|International Laboratory for Brain, Music and Sound Research & Center for Research on Brain, Language and Music, Montreal, QC, Canada.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Lehmann
authors.affiliation: Department of Chiropractic, Université du Québec à Trois-Rivières, 3351 Boul. des Forges, C.P. 500, Trois-Rivières, QC, G9A 5H7, Canada.|Groupe de Recherche en Cognition, Neuroscience, Affect et Comportement (CogNAC), Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Piché
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D059328:Diffuse Noxious Inhibitory Control / Q000502:physiology*; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D008297:Male; D009412:Nerve Fibers / Q000502:physiology*; D059226:Nociceptive Pain / Q000503:physiopathology*; D058748:Pain Perception
keywords: CPM; DNIC; brain activity; human; pain; tactile