title: Impact of a simulated gravity load for atmospheric reentry, 10 g for 2 min, on conscious mice.
abstract: The Japan Aerospace Exploration Agency recently performed a mouse experiment in the International Space Station in which mice were raised for 35 days, retrieved using the Dragon spacecraft, and then harvested for analysis 2 days after splashdown. However, the impact of the retrieval procedure, which exposed mice to 5-10 g for 2 min during atmospheric reentry and splashdown, was unknown. Therefore, the purpose of this study was to examine the impact of a 10 g load for 2 min (using a gondola-type centrifuge with a 1.5-m arm installed at Gifu University) on conscious mice. Plasma corticosterone increased at 30 min after load application and recovered at 90 min. Significant Fos expression was observed in the vestibular nuclei (VeN), paraventricular hypothalamic nucleus (PVN), and central nucleus of the amygdala (CeA). Rearing behavior and food intake were suppressed. Mice with vestibular lesions demonstrated increased corticosterone and Fos expression in the PVN, but neither suppression of food intake and rearing behavior nor increased Fos expression in the VeN and CeA. These results suggest that the simulated gravity load induced a transient stress response, hypoactivity, and a vestibular-mediated suppression of food intake.
authors.affiliation: Department of Physiology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan. zunzunmorita@gmail.com.|Mouse Epigenetics Project, ISS/Kibo Experiment, Japan Aerospace Exploration Agency, Tsukuba, 305-8505, Japan. zunzunmorita@gmail.com.
authors.forename: Hironobu
authors.identifier: http://orcid.org/0000-0001-5390-5100
authors.initials: H
authors.lastname: Morita
authors.affiliation: Department of Physiology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan.
authors.forename: Aoi
authors.initials: A
authors.lastname: Yamaguchi
authors.affiliation: JEM Utilization Center, Human Spaceflight Technology Directorate, Japan Aerospace Exploration Agency, Tsukuba, 305-8505, Japan.
authors.forename: Dai
authors.initials: D
authors.lastname: Shiba
authors.affiliation: JEM Utilization Center, Human Spaceflight Technology Directorate, Japan Aerospace Exploration Agency, Tsukuba, 305-8505, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Shirakawa
authors.affiliation: Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tsukuba, 305-8575, Japan.|Mouse Epigenetics Project, ISS/Kibo Experiment, Japan Aerospace Exploration Agency, Tsukuba, 305-8505, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Takahashi
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D066274:Central Amygdaloid Nucleus / Q000378:metabolism / Q000503:physiopathology; D002498:Centrifugation / Q000009:adverse effects* / Q000379:methods; D003243:Consciousness; D003345:Corticosterone / Q000097:blood; D004435:Eating; D005247:Feeding Behavior; D018470:Gravity, Altered / Q000009:adverse effects*; D008810:Mice, Inbred C57BL; D009041:Motion Sickness / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D009043:Motor Activity; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism / Q000503:physiopathology; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D013026:Space Flight; D013312:Stress, Physiological; D013997:Time Factors; D014726:Vestibular Nuclei / Q000378:metabolism / Q000503:physiopathology
chemical_list: D015415:Biomarkers; D016760:Proto-Oncogene Proteins c-fos; D003345:Corticosterone
keywords: Atmospheric reentry; Corticosterone; Fos; Hypergravity; Vestibular lesion