Abstract
1. In the brain of adult as well as developing rats, localization of Aldolase, Succinic dehydrogenase and Glucose-6-phosphate dehydrogenase was histochemically investgated and compared, and the significance of these enzmes played in the function and metabolism of the brain was discussed.
2. Aldolase and Succinic dehydrogenase revealed nearly the same distribution. Strong activity was demonstrated in the neuropil as well as perikaryon of the grey matter. Shortly after birth both enzymes showed very low activity followed by marked increase in acitivity especially in the neuropil from 2 to 4 weeks after birth. These observations follow that both enzymes might be intimately related to the nervous function by the energy-rich phosphate bonds, which are yieled through the EMBDEN-MEYERHOF path plus KREBS' TCA cycle.
3. Glucose-6-phosphate dehydrogenase showed the localization different from Aldolase and Succinic dehydrogenase. It was generally weak in the neuropil, and strong in the perikaryon and neuroglial cells in the white matter. Moreover, characteristic strong activity was seen in the paraventricular structures, neurosecretory nuclei, lamina granulosa of the bulbus olfactorius accessorius, islands of CALLEJA, nucleus laterodorsalis tegmenti and stria terminalis. Directly after birth strong activity was present in both the grey and white matter, while with advancing age the activity in the neuropil of most portions decreased rather markedly and that of white matter seemed slightly to decrease. From these observations the enzymes, namely the hexose monophosphate shunt, is thought to generally participate in the formation and maintenance of structure of the brain, besides particular functions in some restricted structures.
