視床下部の皮質光誘発電位に対する干渉作用

抄録

It is well documented that the limbic system influences upon the cortical photic evoked potentials via the hypothalamus. Since the different frequency parameters of the stimulation to the limbic system produce various effects upon the cortical photi c evoked potentials, it can be predicted that the different frequency stimulation to various parts of the hypothalamus will produce different effects upon the cortical photic evoked potentials.
Fifty-five ra bbits were utilized for the purpose of this experiment. In the mammillary body, ventromedial nucleus, dorsomedial nucleus, and posterior part of the lateral hypothalamic area, the conditioning electrical stimulation with high frequenc y (100 Hz) attenuated the amplitudes of the cortical photic evoked potentials, while that of low frequency (5 Hz) facilitated them. On the contrary, the condition ing electrical stimulation to the preoptic area, suprachiasmatic and supraopt ic nuclei, field H of Forel, anterior part of the lateral hypothalamic area and the optic tract produced fixed effects upon the cortical photic evoked responses irrespective to the frequency parameters.
These facts imply that the impulses from the limbic system, mainly pass through the posterior hypothalamus where the sympathetic and parasympathetic system s are intermingled and are activated with high and low frequency impulses respectively, It is interesting to note that these bivalent reactions by different frequency parameters were neutralized between 40 to 50Hz frequencies. on the contrary, fixed eff ects upon the cortical photic evoked potentials in the anterior hypothalamus including preop tic are irrespective to the frequency parameters of the stimulation.