title: Extension of recovery time from fatigue by repeated rest with short-term sleep during continuous fatigue load: Development of chronic fatigue model.
abstract: Homeostasis is known to be involved in maintaining the optimal internal environment, helping to achieve the best performance of biological functions. At the same time, a deviation from optimal conditions often attenuates the performance of biological functions, and such restricted performance could be considered as individual fatigue, including physical and mental fatigue. The present study seeks to develop an animal model of chronic or subacute fatigue in which the recovery time is extended through the gradual disruption of homeostasis. We show that repeated short-term rest periods with certain lengths of sleep during continuous fatigue loading extend recovery from spontaneous nighttime activity but not physical performance in comparison with a continuous fatigue-loading procedure. Furthermore, the immobility time in a forced swimming test was extended by repeated short-term rests. These results suggest that repeated short-term rest with certain lengths of sleep during continuous fatigue loading is able to extend the recovery from mental fatigue but not from physical fatigue and that this effect might occur via the disruption of a homeostatic mechanism that is involved in restoring the optimal internal environment.
authors: Division of Biofunction Dynamics Imaging, RIKEN Center for Life Science Technologies, Chuo-ku, Kobe, Japan.|Division of Endocrinology and Metabolism, Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan.
authors: Akinori
authors: A
authors: Kanzaki
authors: Division of Biofunction Dynamics Imaging, RIKEN Center for Life Science Technologies, Chuo-ku, Kobe, Japan.
authors: Takashi
authors: T
authors: Okauchi
authors: Division of Biofunction Dynamics Imaging, RIKEN Center for Life Science Technologies, Chuo-ku, Kobe, Japan.
authors: Di
authors: D
authors: Hu
authors: Division of Biofunction Dynamics Imaging, RIKEN Center for Life Science Technologies, Chuo-ku, Kobe, Japan.
authors: Tomotaka
authors: T
authors: Shingaki
authors: Division of Biofunction Dynamics Imaging, RIKEN Center for Life Science Technologies, Chuo-ku, Kobe, Japan.
authors: Yumiko
authors: Y
authors: Katayama
authors: Division of Endocrinology and Metabolism, Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan.
authors: Hidenori
authors: H
authors: Koyama
authors: Division of Biofunction Dynamics Imaging, RIKEN Center for Life Science Technologies, Chuo-ku, Kobe, Japan.
authors: Yasuyoshi
authors: Y
authors: Watanabe
authors: Division of Biofunction Dynamics Imaging, RIKEN Center for Life Science Technologies, Chuo-ku, Kobe, Japan.
authors: Yilong
authors: Y
authors: Cui
mesh_terms: D000818:Animals; D002908:Chronic Disease; D004195:Disease Models, Animal; D005221:Fatigue / Q000503:physiopathology* / Q000523:psychology; D006706:Homeostasis / Q000502:physiology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000502:physiology*; D012146:Rest / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D013550:Swimming / Q000502:physiology / Q000523:psychology; D013997:Time Factors
keywords: chronic fatigue model; forced swimming test; homeostasis; intermittent water immersion; short-term sleep; spontaneous activity