Intracortical Spread of Epileptic Spikes — Simultaneous Measurement of Magnetic Field and Electric Potential in Rabbits
In many experiments we observed differences between simultaneously measured ECoG and MEG signals concerning the temporal relationship of characteristic features like maxima or minima. This was not surprising despite MEG and extracellular electric potential are functionally related. They are caused by different bioelectric processes. The MEG is mainly caused by intracellular currents of neuronal cell populations. The extracellular electric potential is caused by currents through the cellular membrane. These currents can be elucidated by current source density analysis (CSD).
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