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Simultaneous recording of evoked potentials and T * 2 ‐weighted MR images during somatosensory stimulation of rat
Author(s) -
Brinker Gerrit,
Bock Christian,
Busch Elmar,
Krep Henning,
Hossmann KonstantinAlexander,
HoehnBerlage Mathias
Publication year - 1999
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/(sici)1522-2594(199903)41:3<469::aid-mrm7>3.0.co;2-9
Subject(s) - stimulation , somatosensory system , intensity (physics) , nuclear magnetic resonance , magnetic resonance imaging , somatosensory evoked potential , artifact (error) , functional magnetic resonance imaging , signal (programming language) , neuroscience , chemistry , physics , medicine , psychology , radiology , computer science , optics , programming language
Somatosensory evoked potentials (SEP) and T * 2 ‐weighted nuclear magnetic resonance (NMR) images were recorded simultaneously during somatosensory stimulation of rat to investigate the relationship between electrical activation of the brain tissue and the signal intensity change in functional NMR imaging. Electrical forepaw stimulation was performed in Wistar rats anesthetized with α‐chloralose. SEPs were recorded with calomel electrodes at stimulation frequencies of 1.5, 3, 4.5, and 6 Hz. At the same time, T * 2 ‐weighted imaging was performed, and the signal intensity increase during stimulation was correlated with the mean amplitude of the SEP. Both the stimulation‐evoked signal intensity increase in T * 2 ‐weighted images and the amplitude of SEPs were dependent on the stimulation frequency, with the largest signals at a stimulation frequency of 1.5 Hz and decreasing activations with increasing frequencies. The feasibility of simultaneous, artifact‐free recordings of T * 2 ‐weighted NMR images and of evoked potentials is proved. Furthermore, the study demonstrates—in the intact brain—the validity of functional magnetic resonance imaging for estimating the intensity of electrocortical activation. Magn Reson Med 41:469–473, 1999. © 1999 Wiley‐Liss, Inc.