These Squirrels Are Super Cool
Arctic ground squirrels are one the coolest critters around -- literally. That's because during their hibernation in arctic climates, they can cool their body to below freezing and still survive.
They manage this through a process called supercooling, in which a liquid can reach sub-zero temperatures but still remain fluid. This is possible by reducing the temperature very slowly.
The arctic ground squirrel can drop its internal temperature to as low as minus three degrees Celsius. While another animal's blood would freeze in its veins, the hibernating squirrel's keeps right on flowing.
Scientists at the University of Alaska Fairbanks want to tap into these supercooling talents for human use. One of the applications they foresee is long-distance space travel.
"Humankind is destined to be imprisoned on Earth until we can devise a way to induce a hibernating-like state in people," said lead researcher Brian Barnes, from the university's Institute of Arctic Biology.
Currently, the distance we can travel in space is limited partly by the amount of food, oxygen and water we consume. By putting the astronauts in a temporary hibernation-like state, their heart and blood-flow rates would be lowered, slowing their metabolism substantially and reducing the amount of supplies necessary.
A more down-to-earth application would be to mimic the squirrel's talents to preserve human organs donated for transplant. At the present time, human tissues are viable for four days at most. The arctic ground squirrel can maintain its organs at below-freezing temperatures for weeks.
By replicating the squirrel's trick, transplant organs would have a longer shelf life.
The first step is to understand how the squirrel lowers its temperature and maintains it throughout hibernation.
"We believe that a ground squirrel, when it goes into hibernation, produces chemical messengers that are released from the brain that direct the slowing down of the metabolism," Barnes said. "If we were able to synthesize the same chemical compounds and make them available in an injection, it could be administered to induce a hibernation-like state in humans."
Barnes chose the arctic squirrel for his research, as they are very good at enduring the minus-50-degree conditions of the tundra. The squirrels spend their summers fattening up for the winter, and then in August they tuck into their 2-foot-deep burrows for an eight-month snooze.
The squirrels are also small and very friendly. And plentiful, too, in Barnes' neck of the woods.
"The arctic ground squirrel is not afraid of people," Barnes said. "If you travel into the tundra, they come up to you as if to say, 'Who the hell are you?'"
Barnes' research may do little to enhance human-squirrel relations, however, since it involves luring the squirrel into a cage and then whisking it off to the operating table where its abdominal cavity is cut open and a data logger inserted.
Barnes said that the squirrels are not bothered by the procedure. The critters are anesthetized for the operation, which takes around 20 minutes to complete. "They are very tough animals.... We keep them overnight to make sure they don't tear their stitches and then release them," Barnes said.