海馬起源の眼振解発における乳頭体と透明中隔の役割

乳頭体と透明中隔反覆電気刺激ウサギでみられるアドレナリン眼振を指標とする観察

抄録

In order to determine which of two parts of the brain, the mammillary body or the septal area, is a more important relay nucleus in regard to production of nystagmic responses of hippocampal origin we carried out the following experiments : Adrenaline was given i.v. to rabbits either with repeated electric stimulation of the medial nucleus of the mammillary body or with that of septal area, respectively, and nystagmic responses were recorded before and 10 minutes after injection of adrenaline. Effects of adrenaline in the production of nystagmic responses were then compared in each group of animals.
The results obtained were as follows : Nystagmic responses after adrenaline application tended to be more marked than responses following stimulation (i.e., nystagmic responses before adrenaline) when repeated electric stimulation was given to the medial nucleus of the mammillary body. In contrast, there was no significant difference between the two types of nystagmic responses described above when the same procedure was applied to the septal area.
From these findings we conclude that the medial nucleus of the mammillary body is a more important relay nucleus with regard to production of nystagmic responses of hippocampal origin. This conclusion is compatible with our previous report that nystagmic responses of hippocampal origin are induced, in close correlation with hyperexcitability of adrenergic nerve fibers involved in the neural circuits which link the hippocampus to the oculomotor system in the brain stem.