SAITO Kazuo Department of Hygiene and Preventive Medicine, Hokkaido University School of Med, 医学部, 教授 (80000917)
TAKAKURA Masayuki Department of Hygiene and Preventive Medicine, Hokkaido University School of Med, 医学部, 助手 (90241314)
SAITO Takeshi Department of Hygiene and Preventive Medicine, Hokkaido University School of Med, 医学部, 講師 (40153811)
|Budget Amount *help
¥7,600,000 (Direct Cost : ¥7,600,000)
Fiscal Year 1996 : ¥1,100,000 (Direct Cost : ¥1,100,000)
Fiscal Year 1995 : ¥6,500,000 (Direct Cost : ¥6,500,000)
This study attempted 1) to extract the characteristics of behavioral and morphological changes in aging process of subtypes of senescence accelerated mice (SAM), which include SAM-P8, P10 and R1 characterized with disturbances of learning and memory, brain atrophy and control group respectively, 2) to describe the dynamics of neurotransmission system using ultra high speed reduction system modified with light subtraction method, and 3) to measure the trace elements in the aging process in their brains.
The results of this study are summarized as follows.
1) The alopecia and atrophy of skin were observed more clearly from 9 months age of SAM-P10 and from 14 months age of SAM-P8 compared with SAM-R1. Significantly lower spontaneous activity during night and daytime and body weight at 9 and 13 months age, and significantly more food intake at 13 months age in SAM-P8 compared to SAM-R1, tendency of increase of differences of body weight and food intake from 4 months age between SAM-P10 and S
AM-R1 were observed. Exponential spectrum as an aspect of exitence of chaos was extracted from these time series data.
2) Using 3-dimensional imaging analysis modified with light subtraction method, visualization of exciting process in the neurotransmission system in hippocampus in their brains could be confirmed to supply more information than previous methods, although only under the conditions of keeping fresh slices with high activities for short periods.
3) Using ICP-mass spectroscopy, significantly less zinc concentration at 9 and 12 months of age and copper concentration at 6,9 and 12 months of age, and significantly higher molybdenum concentration at 6,9 and 12 months of age in cerebral cortex of SAM-P10 than of SAM-R1 were found.
These results suggest that different characteristics in behavioral and neurophysiological aspects in aging process between SAM-P8, P10 and R1 may relate to disturbances of metabolic system in their brains. Further studies are necessary to clarify the mechanisms and systems which produce these differemces.