Modulation of somatosensory evoked potentials during coordination between posture and movement

Author(s): Gavrilenko, T., Gantchev, G. N.

Journal/Book: Int J Psychophysiol. 1996; 22: PO Box 211, 1000 AE Amsterdam, Netherlands. Elsevier Science BV. 111-116.

Abstract: Somatosensory evoked potentials (SEPs) elicited during execution of voluntary movements undergo modification in their amplitude ('gating'). We have studied SEP changes during a motor task that includes anticipatory postural adjustment and focal movement. Upright standing subjects were performing fast forward elevation of one arm. The electrical stimulus was presented over the ipsilateral posterior tibial nerve within two different time frames: (1) preceding the EMG activity of femoral biceps muscle, known to be first in occurrence in such task; (2) during this EMG activity, yet before the EMG occurrence in anterior deltoid muscle - prime mover for the forward arm elevation. The following significant changes in SEPs preceding focal movements as compared with control SEPs during quiet stance were found: The early component P42-N50 showed a marked decrease, regardless of its time relation to the anticipatory activity in the leg. Component N50-P60 increased in amplitude, more so when elicited within an earlier time frame. Thus, diminution of amplitude as an expression of gating, was found to exist already before the occurrence of anticipatory postural adjustment activity and to persist during the ensuing focal movement.

Note: Article B Dimitrov, Bulgarian Acad Sci, Inst Physiol, Acad G Bontchev St, BL 23, BU-1113 Sofia, Bulgaria

Keyword(s): somatosensory evoked potential; anticipatory postural adjustment; voluntary movement; gating; posture; balance; VOLUNTARY MOVEMENT; ACTIVE MOVEMENT; ARM MOVEMENTS; STIMULATION; INHIBITION; MUSCLE; MONKEY; CORTEX; INPUT

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