title: Premovement gating of somatosensory evoked potentials after tibial nerve stimulation.
abstract: Somatosensory evoked potentials (SEPs) are attenuated or gated during movement. The mechanism for this includes both centrifugal gating of afferent input and competition with other afferents caused by the movement (peripheral gating). Using a paradigm in which the signal for triggering movement is the electric stimulus for SEPs, we studied the gating of SEPs after tibial nerve stimulation prior to foot movement, and compared it with that during counting task. Significant gating was found for P40 component, which distributed centrally and ipsilaterally to the side of the stimulation, whereas the contralateral N40 component showed no changes. Dissociated gating of P40 and N40 indicates multiple generators of these components, in contrast to the previous view of a single generator dipole projecting tangentially. Together with the previous findings in median SEPs, these gating phenomena should represent a general mechanism for sensori-motor integration in preparation for limb movement.
authors.affiliation: Department of Neurology, Graduate School of Medicine, Kyoto University, Syogoin Sakyo-ku, Kyoto 606-8503, Japan.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Asanuma
authors.forename: Ryo
authors.initials: R
authors.lastname: Urushihara
authors.forename: Kazumi
authors.initials: K
authors.lastname: Nakamura
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Kitaoka
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Sei
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Morita
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shibasaki
authors.forename: Ryuji
authors.initials: R
authors.lastname: Kaji
mesh_terms: D000328:Adult; D001931:Brain Mapping; D003463:Cues; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005528:Foot; D006801:Humans; D008297:Male; D008433:Mathematics; D008606:Mental Processes / Q000502:physiology; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D013016:Sound; D013979:Tibial Nerve / Q000502:physiology*