Functional dissociation of a subcortical and cortical component of high-frequency oscillations in human somatosensory evoked potentials by motor interference.
To identify the possibly divergent impact on early and late high-frequency oscillations (HFOs) in human somatosensory evoked potentials (SEPs), we have studied motor interference effects on the HFOs, and the relevance of such effects for the controversy concerning their origins. While the late HFO is thought to be generated in the somatosensory cortex, there is an ongoing discussion whether the early burst is of cortical or subcortical origin. Movements of the index finger were performed in parallel with median nerve SEP recordings. The intracortically generated N20-SEP and the late HFO were attenuated by the motor task, while the brainstem low-frequency P14-SEP and the early HFO remained unaffected. These differing effects are consistent with a generation of the early HFOs by cortical presynaptic activity in terminals of the thalamocortical projection, and confirm a postsynaptic intracortical origin of the late burst subcomponent.
Gobbelé
René
R
Department of Neurology, University Hospital Aachen, RWTH Aachen, Pauwelsstrasse 30, 52074 Aachen, Germany. rgobbele@ukaachen.de
Waberski
Till Dino
TD
Thyerlei
Dinah
D
Thissen
Melanie
M
Darvas
Felix
F
Klostermann
Fabian
F
Curio
Gabriel
G
Buchner
Helmut
H
D000328:Adult; D001683:Biological Clocks / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D004569:Electroencephalography / Q000379:methods; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011930:Reaction Time / Q000502:physiology*