The record-breaking rodents dubbed “mighty mice” splashed down in a SpaceX Dragon capsule in the Pacific Ocean this time last week. The mice, provided by the nonprofit Jackson Laboratory in Maine, were genetically modified for muscle growth in an experiment to better understand how zero gravity affects the human body.
Astronauts on long-term spaceflight missions experience muscle and bone loss.
Although this atrophy can be mitigated with exercise, experiments like this can help experts understand how the loss occurs and to better manage it.
These mice are just one of many groups of rodents sent to the orbiting space station over the years in the name of research.
The mice began their stay on the space station after docking on December 8.
The experiment was called Rodent Research-19 and it was used to study both myostatin and activin, the molecular signalling pathways able to influence muscle degradation, according to the US space agency NASA.
Researchers believe these pathways could be targets to prevent muscle and bone loss during missions and help with recovery efforts once astronauts return to Earth.
As is often the case with space station experiments, the findings could also help develop therapies for those dealing with muscle and bone loss due to various conditions on Earth.
This includes muscular dystrophy, osteoporosis and diseases that cause muscle wasting like cancer, heart disease, sepsis and even AIDS.
The 40 female mice who flew to the ISS will be compared with a control group of 40 female mice who remained on Earth.
The findings can also be applied to future long-term spaceflight missions to the moon and Mars.
Researcher Se-Jin Lee said in a NASA press release: “The knowledge we gain about microgravity’s effects on muscles and bones will help us to enhance the health of astronauts – both in space and on Earth.
“It will also better understand the promise that myostatin inhibitors hold for the elderly, peopl