Abstract
The present investigation was designed to study the distribution of enzymes in the mamillary body in detail: The latest histochemical methods were applied to the rabbit brain. In the medial nucleus, the nerve cells and the neuropil showed strong succinate dehydrogenase and strong cytochrome oxidase reactions. In the lateral nucleus, the strong reactions were found in the perikaryon of the nerve cells, while the neuropil was weakly or moderately active. The neuropil exhibited fairly strong aldolase activity in the medial nucleus except a thin lowermost layer. In the lateral nucleus, moderate aldolase reaction was almost confined to nerve cells. Strong glucose-6-phosphate dehydrogenase activity was observed in the perikaryon of the nerve cells of the lateral nucleus, while the neuropil of the medial nucleus showed no strong reaction. The neuropil of the lateral nucleus exhibited stronger amylophosphorylase reaction than that of the medial nucleus. The neuropil of the thin lowermost layer of the mamillary body showed moderate or rather strong monoamine oxidase activity and weak aldolase activity.
It is interesting that the neuropil of the lateral nucleus which seems to produce less energy compared with that of the medial nucleus exhibited a little higher activity of cholinesterase than that of the medial nucleus or the same as the latter.
