[Dynamics of transcallosal potentials following local exposure of the cerebral cortex to high temperature]

Experiments were conducted on cats, anesthetized with nembutal. The influence of local heating of the sensomotor cortex on the transcallosum response was examined. It was revealed that heating for short and long periods of limited regions of the cortex of both hemispheres induced a primary depression of the negative component of the transcallosum response at 44 degrees C and above it. The depression was replaced by an irreversible block of both response phases at 47--49 degrees C. It was concluded that the direct inhibitory influence of high temperatures on the cortical neurons was expressed only within the range of extreme temperature incompatible with vital activity of the whole organism. Experiments with the thermal block of the hemisphere region could testify to the fact that the transcallosum responses occurred mainly as a result of the direct irritation of the callosum fibers by stimulating electrodes and entirely reflected the post-synaptic potentials.