Authorship：Lead author   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier  

In mice, genetic differences between inbred strains have been shown for several parameters of sleep and circadian activity rhythms. Our previous studies have demonstrated that CS mice have three remarkable characteristics in the circadian rhythm of locomotor activity: (1) high activity both during the day and night, (2) unstable freerunning period and (3) spontaneous rhythm splitting. In order to characterize sleep properties of CS mice, we compared circadian sleep patterns of CS with those of C57BL/6J and C3H/He mice which have normal circadian activity rhythms. Although C57BL/6J and C3H/He mice exhibited clear daily sleep-wake rhythms in the amount of each sleep parameter (Awake, SWS, PS), CS mice did not show clear rhythms in these parameters. The differences were particularly conspicuous in PS
no apparent day-night differences in the amount of PS, PS counts and PS interval (the interval between successive PS episodes) in CS mice. In addition, the ratio of PS to total sleep time was significantly larger in CS mice than other strains. Of these parameters, the most considerable was PS latency which was extremely short and direct transition from Awake to PS without appearance of SWS frequently occurred in these mice. These results indicate that CS mice may be useful for the understanding of sleep mechanisms and its dysfunction. © 2003 Elsevier B.V. All rights reserved.

DOI： 10.1016/S0006-8993(03)02947-0

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer New York  

In this research, we hypothesized that, in rats, adaptation to high altitude (2500 m) plus training at low altitude (610 m), "living high-training low", improves physical performance at low altitude more than living and training at low altitude (610 m). Rats were divided into four groups: (1) living at low altitude (LL, n=12), (2) living and training at low altitude (LLTL, n=13), (3) living at high altitude (LH, n=12), (4) living at high altitude and training at low altitude (LHTL, n=13). The program for living at high altitude involved raising rats under hypobaric hypoxia (equivalent to 2500 m), and the training program consisted of running on a treadmill at low altitude. All groups were raised at each altitude and trained to run at 35 m/min for 40 min/day, 6 days/week for 6 weeks. During this program, we measured heart rates both at rest and during exercise, and performed running-time trials. The mean heart rate during exercise was lower in groups with training than in groups without training, and the groups receiving training could run longer than the untrained groups. The LHTL group especially showed the lowest mean heart rate during exercise and the longest running time among all groups. After 6 weeks of the training program, all rats had a catheter implanted into the carotid artery, and the mean systemic arterial pressure was continuously measured during treadmill running. The rate of increase of this pressure as the running intensity increased was lower in groups with training than in groups without training, especially in the LHTL group. Finally, we anesthetized all the rats and extracted both the right and left ventricles, and the triceps surae and liver. Training increased the weight of the left ventricle, triceps surae, and liver. The increase in weight of the left ventricle and triceps surae was higher in the LHTL group than in the LLTL group in particular. It appeared that living high-training low may be an effective strategy to improve performance ability at low altitude.

DOI： 10.1007/s004840050135

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Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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