Bioinformatic Study of Transcriptome Changes in the Mice Lumbar Spinal Cord After the 30-Day Spaceflight and Subsequent 7-Day Readaptation on Earth: New Insights Into Molecular Mechanisms of the Hypogravity Motor Syndrome.

The hypogravity motor syndrome (HMS) is one of the deleterious impacts of weightlessness on the human body in orbital space missions. There is a hypothesis that disorders of musculoskeletal system as part of HMS arise in consequence of changes in spinal motor neurons. The study was aimed at bioinformatic analysis of transcriptome changes in lumbar spinal cords of mice after a 30-day spaceflight aboard biosatellite Bion-M1 (space group, S) and subsequent 7-day readaptation to the Earth's gravity (recovery group, R) when compared with control mice (C group) housed in simulated biosatellite conditions on the Earth.

Morphological Study of Myelinated Fibers of the Sciatic Nerve in Mice after Space Flight and Readaptation to the Conditions of Earth Gravity.

We revealed a decrease in the thickness of the myelin sheath and myelin delamination in the tibial nerve of C57BL/6N mice after a 30-day flight aboard the biosatellite Bion-M1. The processes of myelin degeneration continued for seven days after return of the animals to Earth and adaptation to the conditions of natural gravity. Our data add to hypothesis on the role of neurogenic component in pathogenesis of hypogravity motor syndrome.

Myelinated fibers of the mouse spinal cord after a 30-day space flight.

Myelinated fibers and myelin-forming cells in the spinal cord at the L3-L5 level were studied in C57BL/6N mice that had spent 30 days in space. Signs of destruction of myelin in different areas of white matter, reduction of the thickness of myelin sheath and axon diameter, decreased number of myelin-forming cells were detected in "flight" mice. The stay of mice in space during 30 days had a negative impact on the structure of myelinated fibers and caused reduced expression of the markers myelin-forming cells.