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After a 16-year hiatus, Russia has resumed its program of biomedical research in space, with the successful 30-day flight of the Bion-M 1 biosatellite (April 19–May 19, 2013). The principal species for biomedical research in this project was the mouse. This paper presents an overview of the scientific goals, the experimental design and the mouse training/selection program. The aim of mice experiments in the Bion-M 1 project was to elucidate cellular and molecular mechanisms, underlying the adaptation of key physiological systems to long-term exposure in microgravity. The studies with mice combined in vivo measurements, both in flight and post-flight (including continuous blood pressure measurement), with extensive in vitro studies carried out shortly after return of the mice and in the end of recovery study. Male C57/BL6 mice group housed in space habitats were flown aboard the Bion-M 1 biosatellite, or remained on ground in the control experiment that replicated environmental and housing conditions in the spacecraft. Vivarium control groups were used to account for housing effects and possible seasonal differences. Mice training included the co-adaptation in housing groups and mice adaptation to paste food diet. The measures taken to co-adapt aggressive male mice in housing groups and the peculiarities of “space” paste food are described. The training program for mice designated for in vivo studies was broader and included behavioral/functional test battery and continuous behavioral measurements in the home-cage. The results of the preliminary tests were used for the selection of homogenous groups. After the flight, mice were in good condition for biomedical studies and displayed signs of pronounced disadaptation to Earth's gravity. The outcomes of the training program for the mice welfare are discussed. We conclude that our training program was effective and that male mice can be successfully employed in space biomedical research. [ABSTRACT FROM AUTHOR] more...

Profound effects of spaceflight on the physiology of humans and non-human animals are well-documented but incompletely explored. Current goals to undertake interplanetary missions increase the urgency to learn more about adaptation to prolonged spaceflight and readaptation to Earth-normal conditions, especially with the inclusion of radiation exposures greater than those confronted in traditional, orbital flights. The 30-day-long Bion M-1 biosatellite flight was conducted at a relatively high orbit, exposing the mice to greater doses of radiation in addition to microgravity, a combination of factors relevant to Mars missions. Results of the present studies with mice provide insights into the consequences on brain function of long-duration spaceflight. After landing, mice showed profound deficits in vestibular responses during aerial drop tests. Spaceflown mice displayed reduced grip strength, rotarod performance, and voluntary wheel running, each, which improved gradually but incompletely over the 7-days of post-flight testing. Continuous monitoring in the animals' home cage activity, in combination with open-field and other tests of motor performance, revealed indices of altered affect, expressed as hyperactivity, potentiated thigmotaxis, and avoidance of open areas which, together, presented a syndrome of persistent anxiety-like behavior. A learned, operant response acquired before spaceflight was retained, whereas the acquisition of a new task was impaired after the flight. We integrate these observations with other results from Bion-M1's program, identifying deficits in musculoskeletal and cardiovascular systems, as well as in the brain and spinal cord, including altered gene expression patterns and the accompanying neurochemical changes that could underlie our behavioral findings. [ABSTRACT FROM AUTHOR] more...