The Distribution of 65Zn in Mice Brain I. Topographical Peculiarity of the Distribution of Zn in the Brain of Intact Mice

Peculiarity of zinc distribution in mice brain was studied by means of 65Zn. For this purpose, the 65Zn activity of five parts of the brain was investigated at different interval up to 720 hours after subcutaneous injection and autoradiography of the brain was examined after intracerebral injection of 65Zn. The results obtained were as follows :1) The 65Zn activity in each part showed its maximal deposition at the 48 to 120 hour interval. But the activity did not show significant difference one another. 2) The 65Zn activity in each part decreased after the 120 hour interval. The rate at which 65Zn decreased in the Ammon's formation was slower than that in other parts. 3) At the late intervals, five parts of the brain were divided into three groups according to their 65Zn activity. The diencephalon and mesencephalon, pons & medulla oblongata showed lower activity, while the activity of the cerebrum and cerebllum was higher. The Ammon's formation showed the highest 65Zn activity. 4) in autoradioghraphic study, the high density of 65Zn grain was observed in the marginal part of stratum radiatum of h_4,h_5 area which is contact with stratum pyramidale of the hippocampus and stratum multiforme of the dentate gyrus.