MISSOULA - We have all heard of bears hibernating but probably don’t think about squirrels doing the same thing.
This edition of A Wilder View takes a look at why the unique way that squirrels hibernate can help astronauts travel through space.
Hopes of sending people lightyears away into deep space may seem like a work of science fiction.
In real life, we are held back because traveling so far takes a huge chunk of time.
But biologists may be turning this science fiction thinking into fact with the help of a tiny mammal you probably see every day — squirrels.
A solution that NASA has started to help long-term space travel is to put astronauts into a state of hibernation.
For people, this long period of not eating and inactivity would reduce the mass and function of muscles, but this doesn't happen in hibernating animals.
So why not study bears instead? They are the epitome of hibernation after all.
Well, biologists have and still are.
But they have found that larger animals that hibernate like bears are slowing down using energy; they aren’t saving it during hibernation.
Bears are actually losing it, with some grizzly bears having a negative energy savings of 124%.
But smaller hibernating mammals like squirrels tend to save far more energy.
To be able to get through a long winter with no food, hibernating squirrels can slow their metabolism by as much as 99% and yet still manage to maintain their muscles.
This is a key takeaway as people’s muscles would atrophy in such a long sleep.
Squirrels can do this because microbes in their gut generate crucial proteins and amino acids, allowing the squirrels to burn almost no energy when they hibernate with no loss of muscle mass.
To better understand how this unusual hibernation process works, a recent study published in science injected the blood of ground squirrels with tracking agents to allow them to see their bodies’ changes over the winter.
These biologists confirmed a 30-year-old theory called 'urea nitrogen salvage,' which takes nitrogen salvaged from urine and used to make muscle tissues to replace any loss from not eating food.
Essentially meaning they’re recycling their pee.
If what’s happening with the microbes in the guts of squirrels could be used in people, we may be able to put astronauts into a hibernation state without serious muscle loss.
This would also mean they wouldn’t need to take as much food, water and oxygen with them which would help save enormous amounts of weight and fuel.
Having squirrels help us out with space travel is incredible but we could be seeing impacts of these findings right here on Earth.
Over 805 million people around the globe experience muscle depletion as a result of malnourishment which means this could help with areas experiencing famines or low amounts of food.
Sarcopenia is an age-related loss in muscle mass leading to a 30% to 50% decline in skeletal muscle mass in people from 40 to 80 years old.
By harnessing the same process squirrels use to hibernate millions of lives could be helped.
Researchers note that these applications are possible but still quite a way away from being feasible.
A lot of additional work is needed to convert this natural mechanism safely and effectively to people. T
The good news is in the early 90s scientists found evidence that people are capable of recycling small amounts of nitrogen from urine from the same process as squirrels.
This means the necessary process is in place and it just needs to be enhanced.