Eyes like a hawk. Strength of a lion. Speed of a cheetah. Sleep like a squirrel?!? Throughout the ages, warriors have drawn inspiration from nature’s fiercest animals, but DARPA wants to see what hibernating squirrels can teach us about saving wounded soldiers lives.
One of the things that Heller has been trying to figure out for so long is how squirrels and other hibernators manage to regulate their core body temperatures, even as they konk out. Those trials lead to an examination of the human temperature-control system, which lead to a specialized glove-like device, built for the military, that… well, read the article to find out (RTX Glove). Let’s just say the San Francisco 49ers use the things for a reason. So do soldiers in Iraq.
Heller’s partner, Dennis Grahn, leads me down into the basement of the biology center, to check the critters out for myself. He opens up the heavy, metallic doors with a clank. Inside, it’s pitch-black. Massive air conditions roar, blowing cold air over the rows and rows of cages. Using a red-tinted flashlight, he opens one up, and pulls out a plastic drawer. Inside, curled in a ball, packed in cotton, is a squirrel. It’s cold to the touch, as Grahn picks it up, and places it on my palm. It feels more dead than alive.
That condition interests the military, because if wounded soldiers could somehow be put in a squirrel-like state, their wounds would essentially stop bleeding; even seriously-injured patients could be kept alive for much, much longer.
In Darpa-funded tests at the University of Wisconsin, Madison hibernating squirrels are surviving for as long as ten hours, with 60% of their blood drained. Ordinarily, those wounds are enough to kill a rodent in 30 minutes or less.
Cool stuff. But the problem, explains Hannah Carey, a professor at Wisconsin’s School of Veterinary Medicine, is that no one has quite figured out exactly how the critters are pulling it off. Glucose-munching mitochondria, used to operating at very low levels, get all discombobulated, when they get a full meal, again. When oxygen-deprived tissues start getting their 02 again, all kinds of nasty free radicals follow.
Matt Andrews, a Darpa-backed biochemist at the University of Minnesota, Duluth thinks he’s found some enzymes in the pancreas — ones that let the mitochondria feed off of fatty lipids, instead of sugars — that might be responsible for the squirrels’ smooth transition out of hibernation. And it turns out, non-hibernators like us have that enzyme, too. So there’s hope for soldiers, yet.
When our tour of the squirrel-freezer is done, Grahn and I head back upstairs, to Heller’s suite of labs. There’s a small party going on, for a departing grad student. A tiny boom box plays — what else? — The Chipmunks, as we knock back beers and nibble on chips. Finally, the student presents Heller with a present: a set of squirrel-themed mugs.
Wired . . .