0151 Strain Comparison of the Effects of a Spaceflight Analog on Sleep Disruption. (12th April 2019)

• Record Type: Journal Article
• Authors: Campbell, Katrina J; Jiang, Peng; Gao, Vance; Turek, Fred W; Vitaterna, Martha Hotz
• Is Part Of: Sleep. Volume 42(2019)Supplement 1
• Page Start: A62
• Page End: A62
• Publication Date: 2019-04-12
• Subjects: Sleep -- Physiological aspects -- Periodicals; Sleep disorders -- Periodicals; Sommeil -- Aspect physiologique -- Périodiques; Sommeil, Troubles du -- Périodiques; Sleep disorders; Sleep -- Physiological aspects; Sleep -- physiological aspects; Sleep Wake Disorders; Psychophysiology; Electronic journals; Periodicals; 616.8498
• DOI: 10.1093/sleep/zsz067.150
• Languages: English
• ISSNs: 0161-8105

Abstract

Abstract: Introduction: Hindlimb unloading (HLU) is the most prevalent simulation of microgravity on earth. It captures several effects of spaceflight including: cephalic fluid shift, partial unloading of the hind limbs and spine, as well as sleep and immunologic impairments. Sleep is uniquely important because many of these other impairments have been found in sleep deprivation models and sleep is known to be impaired in humans in microgravity. In order to study how differences in physiology may affect adaptation to microgravity, we monitored sleep and other measures in two mouse strains in the HLU protocol and compared them. Methods: Sleep/wake states were determined from EEG/EMG recording, combined with simultaneous HLU for the first time using a novel, lab-devised system. 12 female C57BL/6J (B6) and C3H/HeJ (C3H) mice were studied: six per strain underwent HLU, while six underwent sham manipulation. After a baseline recording period, mice were subjected to 4 weeks of HLU or sham unloading. Mouse body weight and composition and gut microbiome were also compared. Results: The total amount of time spent in wake or sleep states did not change for either strain. Sleep fragmentation in B6 mice was increased but remained stable in C3H mice. Conversely, unloaded C3H mice had lower body weights and fat percentage than their control counterparts but unloaded B6 mice remained comparable. Strain-dependent differences in the gut microbiome were also found. Conclusion: The effects of hindlimb unloading on B6 and C3H mice varied considerably, affecting different aspects of each strain's physiology. Our laboratory has recently performed an experiment on the International Space Station using these two mouse strains in which the same outcomes were monitored. These mice were sacrificed after 25 and 75 days of spaceflight and final tissue samples and fecal material are expected to be returned to earth in late January, allowing us to present some analyses comparing slaceflight and HLU mice at Sleep 2019. By making these comparisons, we can question the underlying mechanisms which cause the physiological changes associated with HLU and spaceflight. Support (If Any): NASA grant NNX15AL05G