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Abstract #3262

Toward Direct Detection of Neuronal Magnetic Fields Using MRI: Local and Three-Dimensional Mapping of Somatosensory Evoked Fields in the Rat Brain

Masaki Sekino1, 2, Tomoaki Takewa1, Dongmin Kim1, 2, Yusuke Inoue1, 2, Hiroyuki Ohsaki1

1Department of Electrical Engineering and Information Systems, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, Japan; 2Exploratory Research for Advanced Technology, Japan Science and Technology Agency, Bunkyo-ku, Tokyo, Japan

Detection of weak magnetic fields arising from neuronal electrical activities using MRI is an attractive but challenging topic in functional MRI. We measured three-dimensional distribution of local field potentials in the rat somatosensory cortex using a 16-channel microelectrode array with a spatial resolution of 0.3 mm. Local distributions of electric current and magnetic field were calculated from the measured potentials. The resulting field magnitude of 2.8x10-12 T was comparable to the theoretical sensitivity limit of MRI.

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