title: Movements modulate cortical activities evoked by noxious stimulation.
abstract: To evaluate the effects of movement on cortical activities evoked by noxious stimulation, we recorded magnetoencephalography following noxious YAG laser stimulation applied to the dorsum of the left hand in normal volunteers. Results of the present study can be summarized as follows: (1) active movement of the hand ipsilateral to the side of noxious stimulation resulted in significant attenuation of both primary and secondary somatosensory cortices (SI and SII) in the hemisphere contralateral to the stimulated hand (cSI and cSII). Activity in the hemisphere ipsilateral to the side of stimulation (iSII) was not affected. (2) Active movement of the hand contralateral to the side of noxious stimulation resulted in significant attenuation of cSII. Activity in cSI and iSII was not affected. (3) Passive movement of the hand ipsilateral to the side of noxious stimulation resulted in significant attenuation of cSI. Activity in cSII and iSII was not affected. (4) Visual analogue scale (VAS) changes showed a similar pattern to the amplitude changes of cSII. These results suggest that activities in three regions are modulated by movements differently. Inhibition in cSI was considered to be mainly due to an interaction in SI by the signals ascending from the stimulated and movement hand. Inhibition in cSII was considered to be mainly due to particular brain activities relating to motor execution and/or movement execution associated with a specific attention effect. In addition, since VAS changes showed a similar relationship with the amplitude changes of cSII, cSII may play a role in pain perception.
authors.affiliation: Department of Integrative Physiology, National Institute for Physiological Sciences, Myodaiji, Okazaki 444-8585, Japan. nakata@nips.ac.jp
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nakata
authors.forename: Koji
authors.initials: K
authors.lastname: Inui
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Wasaka
authors.forename: Yohei
authors.initials: Y
authors.lastname: Tamura
authors.forename: Tuan Diep
authors.initials: TD
authors.lastname: Tran
authors.forename: Yunhai
authors.initials: Y
authors.lastname: Qiu
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wang
authors.forename: Thi Binh
authors.initials: TB
authors.lastname: Nguyen
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Kakigi
mesh_terms: D000328:Adult; D001931:Brain Mapping; D004574:Electromagnetic Fields; D005073:Evoked Potentials, Somatosensory / Q000502:physiology* / Q000528:radiation effects; D007839:Functional Laterality; D006225:Hand / Q000294:innervation / Q000502:physiology; D006801:Humans; D007834:Lasers; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography / Q000379:methods; D008297:Male; D009068:Movement / Q000502:physiology* / Q000528:radiation effects; D010147:Pain Measurement / Q000379:methods; D010812:Physical Stimulation / Q000379:methods; D011930:Reaction Time; D013003:Somatosensory Cortex / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*