June 10 2015, 9pm in Alaska, tune in to KAKM Science Wednesdays, Alaska Public Media, for Frontier Scientists’ ARCTIC GROUND SQUIRREL feature.
Ground squirrels, described as cute furballs or the perfect yuppie pet, live unusual lives in the Arctic. They survive body temperatures below freezing and use a superpowered internalized clock to stay on schedule. Determining how the Arctic ground squirrels’ impressive internal clocks stay on track can help us learn to treat a wide range of human diseases. Scientist Loren Buck described: “So many of the disease states – pathologies – that are exhibited by humans today are characterized by a breakdown in clock function,” including seasonal defective disorder, cardiovascular disease, diabetes, alzheimers, old age senility, and more. “Virtually any pathology that you can think of is tied to clock function.”
In this Frontier Scientists special scientists work in the field and in the lab to decode the amazing abilities of the Arctic ground squirrel. Featured scientists include Loren Buck, University of Alaska Anchorage Department of Biological Science professor, and Brian Barnes, University of Alaska Fairbanks Institute of Arctic Biology director and Biology and Wildlife Department professor.
After watching a Frontier Scientists program on KAKM navigate to www.FrontierScientists.com to explore research topics in more detail and pose questions directly to featured scientists. “We want to let travelers, teachers, students, aspiring scientists, and anyone else interested in science feel as if they are with scientists as they track grizzlies or take the temperature of permafrost in a borehole,” explained Liz O’Connell, Frontier Scientists director.
Arctic ground squirrel physiology has adapted to help them survive the Arctic’s extreme and variable environment. In the summer their exacting circadian clock helps them keep a workday schedule of waking and sleeping, despite the Arctic’s midnight sun. In the winter the squirrels hibernate in underground burrows.
The Institute of Arctic Biology at the University of Alaska Fairbanks has a lab which can house upwards of 200 Arctic ground squirrels. In boxes with bedding, the squirrels hibernate for an 8 month stretch without food or drink. Their health is monitored with temperature sensors. Hibernating Arctic ground squirrels can sustain a core body temperature below freezing, measured at just -2.9°C [26.78°F], yet they don’t turn to ice. It’s the lowest known temperature hit by any vertebrate.
Every two to three weeks Arctic ground squirrels have to warm themselves out of hibernation torpor. Their bodies change from a frozen temperature to about 37°C [98.6°] long enough for the squirrels to sleep. “Sleep is something all animals need on a regular basis… even if you are a hibernating Arctic ground squirrel, except you only sleep one day every three weeks,” Barnes said. He noted the squirrels “Don’t leave their burrow. In fact they stay within their nest and actually stay curled in a ball with their tail tucked over their head, just as in torpor. What they do is: go to sleep. They enter regular sleep stages of slow-wave and REM sleep, just as they do in the summer, and sleep for 8 or 9 hours. They rearrange their nest for a little bit and then go back into torpor.” Sleeping for a time helps the squirrels protect their brain and avoid the impacts of prolonged sleep deprivation.
Lesa Hollen, a neuroscientist with a Master of Science from the University of Alaska Fairbanks, pointed Frontier Scientists to this video https://www.youtube.com/watch?v=jtWntEftFuk which depicts an Arctic ground squirrel coming out of torpor. By viewing the temperature overlay you can see that the squirrel’s head warms up first, its tail-end last. Hollen wrote: “Here is research completed in Kelly Drew’s Lab at UAF showing actual visualization of Arctic Ground Squirrel Rewarming. Notice they can control rewarming to different area’s of their bodies. Phenomenal mechanisms.”
The video is part of the hibernation biology research taking place in Kelly L. Drew’s lab in the University of Alaska Fairbanks’ Institute of Arctic Biology. Drew is a professor of Chemistry and Biochemistry at UAFairbanks. Her research looks into how Arctic ground squirrels protect and regulate their brains during hibernation.
“This is a species that has been in Northern Alaska and across Northern Canada for tens of thousands of years. They are permafrost specialists, they are supremely adapted to the tundra lifestyle,” explained Buck. Now they’re facing a changing climate. Buck said “You have this animal that has evolved in a very extreme environment that’s been relatively constant over the last 10,000 years and now that environment is changing radically.” Warming temperatures are expected to cause increased precipitation in the Arctic, meaning Arctic ground squirrels will have to deal with heavy spring snowfalls with the potential to bury the food they rely on after emerging from hibernation. Warming temperatures also cause ‘shrubification’, encouraging shrub growth instead of the growth of small tundra plants the squirrels favor.
David Gilichinsky and other scientists with the Institute of Cell Biophysics, Russian Academy of Sciences, recovered seeds and plant tissue from the Narrow-leafed campion (Silene stenophylla) that were frozen over 30,000 years ago. The plant matter had been gathered by ground squirrels and squirreled away in burrows. There, it remained frozen in permafrost until being recovered in 2007. The scientists managed to grow viable living plants of Narrow-leafed campion with the seeds and plant tissue recovered. It’s an impressive feat, and just one more example of how Arctic ground squirrels are helping modern-day science progress.
Laura Nielsen 2015
Frontier Scientists: presenting scientific discovery in the Arctic and beyond