[Heterotopic fields of transcomissural responses and their interaction]

The commissural afferents come to the cat sensomotor cortex from a considerable area of the stimulated hemisphere. The "receptive fields" were concentric and somewhat asymmetrical in respect to the reference point. The "receptive field's" topic depended on the site of recording electrode. Two types of transcommissural potential fields are revealed: with excitatory center and depressing periphery (1) and (2) with excitatory periphery and depressing center. The transcommissural fields of separate points overlapped in the area of the fastest density of callosal connections. "Receptive fields" of extracallosal potentials in callosectomized animals were smaller and less labile. The fields of extracallosal responses and transcommissural potentials interacted with each other. The transcommissural "receptive fields" are supposed to appear in result of interaction among callosal, extracallosal and intracortical flows of excitation emphasizing the excitation coming to the "receptive field's" center through the corpus callosum.