新・旧・古皮質系の発作発射（Seizure Discharge）に関する電気生理学的研究—てんかんの臨床に対する推論を加えて

Electro-physiological Study of seizure discharges in neo-, paleo, and archi-cortical systems, with special references to clinical problems of the epilepsies.

I．緒論

　Hans Berger以来この20〜30年にわたつて，脳の電気的活動と脳の活動状態との関係については，極めて多くの研究が行われ，色々と特徴的な関連様式が知られて来た。臨床的方面からは，てんかん諸型と脳の異常な電気的活動との密接な関連性を中心として，Gibbs ＆ Gibbs^24），Penfield ＆ Jasper^58）その他により多くの研究が行われ，詳細な臨床脳波学的体系が形成されて来ている。これに伴い，1950年前後より脳の生理学も，意識の問題を中心として著しい発展をみせ，Moruzzi ＆ Magoun^55）及びその一派は，網様体賦活系（reticular activating system）が脳全体の活動水準の維持に最も重要な役割をもつことを認め，Jasper^33）は，広汎性視床投射系（diffusethalamic projection system）を，同様な機能において重視している。これらの概念を中心として，中脳網様体―視床―新皮質系の機能に関しては，かなり統一的見解がすでに形成されている。

　The author studied the seizure discharges inneo-, paleo-, and archi-cortical systems about 80ruralized cats. The following results were obtained.

　(1) The generalized seizure discharge induced 1w the transcranial electroshock with thresholdvoltage was originated in the neocortex, thenpropagated to the caudate nucleus and thalamusand finally to the whole brain. Usually it endedsimultaneously in the whole brain, but sometimesit showed the dissociated pattern among the threecortical systems. In repeated electroshocks, thehippocampus was most susceptible to the seizuredischarge.

　(2) By local electrical stimulation with threshold voltage, the localized seizure dischargeswere induced in the neocortex, amygdala andhippocampus. The localized seizure discharges inthese three cortical portions propagated to respective related suhcortical structures with similar wave-forms and manners of termination (fromthe neocortex to the caudate nucleus and thalamus; from the amygdala to the anterior part ofthe hypothalamus and globus pallidus; from thehippocampus to the posterior part of the hypothalamus and septal region etc.), as suspected bythe observation on the generalized seizure discharge induced by the transcranial electroshock. Some features in generalized and localized seizure discharge in this experimental results werediscussed in connection with the some featuresin the generalized epilepsies and the partial epilepsies in clinic respectively.

　(3) The experiment on the effects of the psychotropic drugs on the seizure discharges showedthat meprobamate inhibited predominantly theneocortical system and chlorpromazine inhibitedpaleo-, and archi-cortical system and pentobarbitedsupressed diffusely the whole brain but predominantly the neocortex.

　The author considered these experimental results with reference to the different clinical features of these psychotropic drugs, especially inthe treatment of the epilepsies and EEG activation.

　(4) The reticular and hypothalamic activatingsystems showed facilitatory effects on the susceptibility to localized seizure discharge of the neocortex, and inhibitory effects on that of theamygdala and hippocampus. The different effectiveness of sleep-EEG-activation and cardiazol-EEG-activation in epilepsies were discussed fromthe above mentioned experimental results.

　(5) On the ontogenetic differences of theseizure discharges, the author reported that theimmature cats have the higher seizure thresholdon the amygdala and hippocampus and lower onein the neocortex comparing with the adult cats. This results were considered in connectionwith the clinical facts that the age of onset ofthe psychomotor epilepsy was fairly older thanthat of the other types of the epilepsies.