It's been below zero for several days here in Bozeman. I completely understand hibernation at this point! As I started researching animals that were most resistant to the cold, I was shocked to see the Alaskan Wood Frog at the top of the list.
An amphibian? It's true.
According to National Geographic, the Alaskan Wood Frog can survive subarctic temperatures for several weeks. And they can go into a freeze-like hibernation for up to 7 months. The heart and lungs of the frog actually stop beating and functioning but then can restart when the frog unthaws.
Chemicals called "cryoprotectants" act as a kind of anti-freeze to keep the tissues from actually freezing.
Researcher David Denlinger told reporter Claire Asher the BBC that cryoprotectants form bonds with water molecules that prevent the water molecule from forming ice. This means that the water doesn't freeze below 32 degrees Fahrenheit. Urea, glucose, and glycogen serve as the cryoprotectants and freezing temperatures turn on specific genes that deliver the cryoprotectants to cells. Therefore the cryoprotectants protect the cell damage caused by preventing ice crystals from forming.
Not only is the research into Alaskan Wood Frogs fascinating, it has valuable potential for medicine.
If we could learn how to mimic the freezing and unfreezing of human organs without cell damage, we could transport organs for transplant more safely and successfully.