Interhemispheric asymmetry of homotopic transcallosal responses of the auditory cortex in the cat.

In acute experiments on 29 d-tubocurarine immobilized cats, with topographical pick-up of potentials from 150-170 symmetrical points of the auditory cortex, the interhemispheric asymmetry of homotopic transcallosal responses were studied. It was established that in the majority of the animals the potentials in the right hemisphere had a greater amplitude and shorter latent periods as compared with the responses of the left hemisphere. A dependence of the properties of the interhemispheric asymmetry on the sex of the animal was noted. In females the asymmetry was characterized by a right hemispheric tendency and by a greater magnitude as compared with males. The maximal magnitude of the asymmetry was detected in the group of pregnant females. The hypothesis is proposed to the effect that the established polarity of transcallosal influenced in the auditory cortex is associated with the dominance of the right hemisphere in the organization of spatial audition.