The influence of lorazepam on somatosensory-evoked fast frequency (600 Hz) activity in MEG.
The generators of high frequency bursts (600-Hz activity) detected at the parietal scalp over the primary somatosensory cortex after electrical stimulation of peripheral nerves are not yet known. We investigated the influence of benzodiazepine on the somatosensory-evoked 600-Hz activity by means of neuromagnetic measurements and source analysis. After oral administration of lorazepam, the latency of the 600-Hz burst activity was increased; specifically later peaks were delayed more than earlier peaks. In contrast, the latency of the concurrent primary cortical low frequency response (N20m) was not significantly changed. The source strengths of both N20m and 600-Hz bursts were significantly increased. Our results provide evidence for two components of the 600-Hz activity with a different generator structure.
Department of Neurology, Biomagnetisches Zentrum, Friedrich-Schiller-Universität Jena, Philosophenweg 3, 07740, Jena, Germany. haueisen@biomag.uni-jena.de
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J
Haueisen
T
T
Heuer
H
H
Nowak
J
J
Liepert
C
C
Weiller
Y
Y
Okada
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G
Curio
D000328:Adult; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects*; D006801:Humans; D008140:Lorazepam / Q000494:pharmacology*; D015225:Magnetoencephalography; D008297:Male; D011930:Reaction Time / Q000187:drug effects
D008140:Lorazepam