自律中枢と前庭神経核について

THE AUTONOMIC CENTER AND VESTIBULAR NUCLEI

　Ⅰ．まえがき

　現在，視床下部hypothalamusが自律神経系の最高の中枢であるということには異論がない。視床下部は前脳の内で発生学的にはもつとも古い部分である。しかもその突起が下垂体の後葉になり，口腔の外胚葉からのびた突起（前葉）とともに下垂体を作つているので，発生学的に見ても視床下部は下垂体と密接な関係にあることがわかる。前庭神経核の直接刺激が自律神経反応を示すことは周知の事実であるが，最近，私どもは自律中枢と前庭神経核との連絡路に関して，新知見を証明してきた。たまたま，昨年，第14回前庭研究会（会長，石井英男教授）に招待され特別講演を行なつたが，その時の口演内容を中心として，その後に得た知見を加えつつ記述しようと思う。

On the basis of the consideration that the septal region, preoptic area and hypothalamus are closely related to each other with respect to their functions and fiber connections, they have been considered as a functional unit under the name of "Septo-preoptico-hypotha-lamic system" ("SPH-system"). The "SPH-system" has been divided into three areas: ar-ea parasympathica A (consisting of the septal region, preoptic periventricular stratum and hypothalamic periventricular stratum), area sympathica B.(the medial preoptic area and medial hypothalamic area) and area parasym-pathica C (the septal region, lateral preoptic area and lateral hypothalamic nucleus). Of these areas, area sympathica B is most clo-sely related to the vestibular nuclei via the dorsal longitudinal fasciculus, because both ascending and descending fibers of this fas-ciculus belonging to area sympathica B ter-minate partly in the vestibular nuclei and the vestibular nuclei send their axons to the dorsal longitudinal fasciculus. The vestibular components of the medial longitudinal fasci-culus also connect with the dorsal longitudi-nal fasciculus in the interstitial nucleus of Cajal and in the central gray substance of the midbrain. By these fiber connections between the vestibular nuclei and area sym-pathica B, the vestibular nuclei are supposed to produce sympathetic responses.