1965 Volume 5 Issue 2-3 Pages 102-117
1. Mice of dd strain were irradiated by various dosages of X-ray, (50. 100. 200. 300 and 400r) on the 1st day birth, and 100, 200, 300, 400, 500, 600, 700 and 800r, on the 5th day. The brain and somatic development of them were studied both macro-and microscopically as well from the 1st day to the 1st year. Food motor conditioned reflex by olfactory analyser and motor conditioned reflex by thermal analyser were applied to detect processes of differentiation of motor reaction of irradiated mice. 2. When X-ray of more than 200r was irradiated, there were found decrease of the volume of the cerebrum, insufficient development of the occipital region of the cerebral cortex, irregular arrangement of the sulcus, folia and Purkinje cells in the cerebellum. Enlargement of the cavity of the lateral ventricle, serious hydrocephaly, large vacuoles extending from the tectum mesencephali to the cerebellum and brain stem were observed. In those irradiated soon after the 1st day of birth, cellular masses forming rosettes, many heavily stained small droplets and degenerated cells were observed within 3-5 hours in the parietal region of the cerebral cortex, granular layer of the cerebellum and hippocampus. These degenerated cells and small dropelts were gradually disappeared until the 20th day. After the 30th day, venous stagnation and perivascular oedema appeared in all portions of the brain and such findings were seen more than one year. Necrosis of Purkinje cells occured at the beginning of the vascular changes and continued thereafter. 3. By the food motor conditioned reflex by olfactory analyser it was found that the appearanse of the reaction delayed for 4-5 days in mice irradiated more than 200r. 4. By the motor conditioned reflex by thermal analyser it was observed that the appearance of the motor reaction delayed for 4-5 days in mice irradiated more than 200r. 5. The retardation of these developments was not so remarkable compared with those irradiated prenatally.
