[Origin of components of the transcallosal potential in the motor cortex]

The potentials of positive--negative configuration alone inverted on insertion of the leading electrode into the cortex. The inversion of responses in the point symmetrical to stimulation site occurred at the level of the II--II layers; in the point of maximal activity--at the V layer. The negative-positive transcallosal potentials as well as extracallosal responses did not invert. Transcallosal potentials of different configuration seem to be due to interaction of several flows of excitation within the cortex of recipient hemisphere. Inhibition processes seem to participate in forming the focus of transcallosal excitation.