両側聴領皮質間の相互作用に関する実験的研究

抄録

Interaction between the primary evoked respone of the cat auditory cortex and the transcallosal volley have been studied under nembutal anesthesia.
By pure tone stimulation typical on-and offresponse were produced in the auditory cortex, both consisting of the biphasic waves (initial positivity followed by the negativity in the surface, deeeper position from surface).
The first component of the on-response, having after the shock. As for the second component, the was more prolonged.
Off-response, although less frequently observed, was similiar in shape to the on-response, except the former longer latency.
Evoked potential elicited by the click was not different from it by the pure tone in on-response.
Transcallosal response of the ectosylvian gyrus elicited by 1_??_10 stimulation of the homotopical cortical point reptitively, was biphasic (positivenegative at the surface, negative-positive at deep), the peak and 40 msec duration.
Primary evoked response, both first and second component, could be abolished completely or reduced in size, if the conditioning transcallosal potential the fromer could be as late as 60 msec prolonged in some cases.
Primary response could be augumented in size, if the transcallosal volley proceeded by about 50_??_100 msec in physiological homotopical point stimulation.
The transcallosal response was also reduced in size by the conditioning pure tone, when the conditioning-testing intervals was about 10 msec. However the former was never augumented by the latter conditioning.
It was confirmed that the section of the transcallosal body abolished the transcallosal response, leaving the primary response unchanged.
It is suggested that facilitatory and inhibitory interaction between transcallosal stimulation and primary response of the auditory cortex may exert a role in the fine integrative discrimination of sound.