Mice and Microgravity: How Clever Rodents Adapt to Life in Space (Video)

Mice on Earth may like to run in the wheels, but mice in space apparently take advantage of microgravity to turn around bouncing off the walls.

New study of mice living aboard the International Space Station suggests such projects could reveal Key ideas to support human journeys to Mars and beyond, the scientists added.

A mission on Mars and back would take years, but scientists do not know how a crew will adapt or suffer for so long in space. Space flights involve exposure to microgravity, radiation, isolation and a host of other factors physical and psychological risks for astronauts.

Related: A study of NASA twins reveals the effects of space travel on the human body

(Image: © NASA / Dominic Hart)

The study of rats and laboratory mice is an obvious way for scientists to determine the potential effects of a space flight without endangering astronauts. "As rodents grow and age much faster than humans, the study of model organisms allows scientists to study diseases that can take years or even decades to develop – humans"The lead author of the study, April Ronca, a space bioscientist at NASA's Ames Research Center in Moffett Field, Calif., Told Space.com.

However, previous work on rodents in the space The animals were often stolen in poorly equipped devices to reveal what they were really doing in flight and how well they fit into life in space, the researchers wrote. For example, in 2013, 45 male mice flew for 30 days on the Russian non-screwed Bion-M1 spacecraft, but malfunction of the food dispenser and other equipment failures killed about two-thirds mouses. The quality of the video recordings of the mice also declined precipitately after the first week, as debris obscured the camera's lenses.

Researchers have therefore designed a new, improved rodent facility to be sent to NASA's NASA Rodent Habitat Space Station. During the first two uses of this habitat, the NASA Rodent Research-1 mission, scientists recorded videos of 20 female mice for 17 to 33 days. A group of similar mice was kept on the floor and monitored for comparison during each procedure.

NASA's Habitat for Rodents has been designed to house mice in groups, which reduces their stress levels and helps scientists monitor their social activity. The habitat also sports grids on which mice can grab and bounce. The habitat also provides both a relatively large space for the mice to move in a smaller area, they can retreat and adopt the typical clustering behavior of the mice.

NASA's rodent habitat design also helped keep his lenses clear enough throughout the mission. "The camera's lenses are placed in the habitat so as to reduce lens exposure to debris and suspended fluids," Ronca said. "More recently, a lens cleaning step has been integrated into the rodent research system, which has further improved the quality of the image."

In these initial tests, scientists discovered that mice in the space were active and mobile throughout the experiment, exploring their habitat and adapting to a range of typical behaviors. the species, such as feeding, grooming and snuggling together. Rodents quickly adapted to their new weightlessness, for example by anchoring in the walls of the habitat with their hind legs or tail and stretching their bodies. This pose was similar to that of mice on Earth standing on their hind legs to explore their environment.

Throughout their stay on the space station, the mice explored the entire habitat. At the end of the mission, the researchers reported that their weight was about the same as that of their counterparts on the ground and that their coat was in excellent condition, which is a sign of good health.

A unique behavior was observed within seven to ten days of launch: the youngest but not the oldest mice of the experiment began to circle around the walls of the habitat. This "race track" quickly evolved into a coordinated group activity. The researchers noted that this was like exercises in which the human crew regularly participated.

But scientists do not know why these mice started running. Mice with the chance to run on a spinning wheel in nature will do about as much as captive mice, suggesting that circles of all kinds are something that mice like to do. Or, such circles are the type of abnormal repetitive behavior that, according to previous research, has shown that animals behaved under stress. However, researchers believe that strapping in space is not a likely cause of stress because the mice were in excellent health, exhibited no obvious signs of stress, and otherwise behaved otherwise.

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Of course, the particular conditions imposed by spaceflights might have prompted us to go around in circles. Bones in the inner ears of mice and humans help the body maintain its balance, but microgravity, the constant feeling of free fall felt in orbit can be uncomfortable. Circles can generate forces to stimulate the inner ear and help rodents feel comfortable, the researchers said. In the future, scientists plan to identify molecular and cellular changes in mice to better understand the causes of encirclement, Ronca said.

And the shorter lifespan of mice could help scientists shed light on long-term human spaceflight. "The mice flew up to 37 days, which corresponds to about 18 months for humans," said Ronca. "The results of long-term rodent studies are important to know how to protect the health of astronauts who will embark on long-term exploration missions, and can help treat diseases on Earth such as the removal of immune system, muscle atrophy and bone loss. "

Detailed scientists their discoveries online April 11 in the journal Scientific Reports.

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