Impact of a simulated gravity load for atmospheric reentry, 10 g for 2 min, on conscious mice

J Physiol Sci. 2017 Jul;67(4):531-537. doi: 10.1007/s12576-017-0526-z. Epub 2017 Feb 9.


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.

Keywords: Atmospheric reentry; Corticosterone; Fos; Hypergravity; Vestibular lesion.

MeSH terms

  • Animals
  • Biomarkers / blood
  • Central Amygdaloid Nucleus / metabolism
  • Central Amygdaloid Nucleus / physiopathology
  • Centrifugation / adverse effects*
  • Centrifugation / methods
  • Consciousness*
  • Corticosterone / blood
  • Eating
  • Feeding Behavior
  • Gravity, Altered / adverse effects*
  • Mice, Inbred C57BL
  • Motion Sickness / etiology
  • Motion Sickness / metabolism
  • Motion Sickness / physiopathology
  • Motor Activity
  • Paraventricular Hypothalamic Nucleus / metabolism
  • Paraventricular Hypothalamic Nucleus / physiopathology
  • Proto-Oncogene Proteins c-fos / metabolism
  • Space Flight*
  • Stress, Physiological*
  • Time Factors
  • Vestibular Nuclei / metabolism
  • Vestibular Nuclei / physiopathology


  • Biomarkers
  • Proto-Oncogene Proteins c-fos
  • Corticosterone