Effects of movement on somatosensory N20m fields and high-frequency oscillations.
Somatosensory evoked fields were recorded to determine the effects of movement and attention on high-frequency oscillations during active finger movements of the ipsilateral and contralateral sides in response to electrical stimulation of the median nerve. A whole-scalp neuromagnetometer was used to record somatosensory evoked fields from eight subjects following electric median nerve stimulation at the wrist. The following three sessions were performed: (1). rest, (2). movement of fingers on the ipsilateral in response to stimulation and (3). movement of fingers on the contralateral in response to stimulation. The somatosensory evoked fields with a wide-bandpass (0.1-1000 Hz) were recorded. High-frequency oscillations and N20m were separated by subsequent high-pass (> 300 Hz) and low-pass (< 300 Hz) filtering. The maximum amplitude of high-frequency oscillations decreased during finger movements accompanying a decrease in somatosensory N20m dipole strength. Activation of the motor cortex appeared to suppress both the amplitude of high-frequency oscillations and the N20m dipole strength.
Inoue
Ken
K
Department of Clinical Neuroscience and Therapeutics, Hiroshima University, Graduate School of Biomedical Sciences, Tokyo, Japan. kinoue@hicat.ne.jp
Harada
Toshihide
T
Kaseda
Yumiko
Y
Mimori
Yasuyo
Y
Hashizume
Akira
A
Hashimoto
Isao
I
Matsumoto
Masayasu
M
D000328:Adult; D000344:Afferent Pathways / Q000502:physiology*; D000368:Aged; D001683:Biological Clocks / Q000502:physiology*; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D005385:Fingers / Q000294:innervation / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000502:physiology*; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology; D009068:Movement / Q000502:physiology*; D009431:Neural Conduction / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology*