Arctic ground squirrel chronobiology; Wake up, guys, my biological clock says it’s…spring?

10 July 2014 by Liz O'Connell, posted in General

Hibernating arctic ground squirrels can lower their core body temperature to minus 3 degrees Celcius. / Image Erin Hooley, University of Alaska Anchorage Office of Advancement

Hibernating arctic ground squirrels can lower their core body temperature to minus 3 degrees Celcius. / Image Erin Hooley, University of Alaska Anchorage Office of Advancement

Biology major Brady Salli spends seven days a week in the vivarium making sure UAA’s arctic ground squirrels are fed, watered and, for those that are hibernating, tucked snugly into clean cotton batting. The kicker? He has to maintain a random schedule so the animals don’t “cheat” off of him.

Professor Loren Buck, Department of Biological Sciences, is Brady’s mentor and boss. He is leading a team of researchers in a four-year National Science Foundation (NSF) grant-funded study of the effects of light and dark on arctic ground squirrels’ circadian rhythms. Most Alaskans understand these biological clock-driven processes primarily as the culprit behind a sleepless night, jet lag or Seasonal Affective Disorder. In the land of the midnight sun (and, conversely, the land of the midday moon), we’re a little hard-pressed to look at the sky and determine bedtime or mealtime during our bright summers and dark winters. We rely heavily on clocks and routine. But what of Alaska’s animals? How important is it for them to stay on track during extended light and dark periods? The arctic ground squirrel is one hardy Alaska resident that can help researchers better understand the science of circadian rhythms and biological clocks, a field called chronobiology.

Professor Loren Buck releases an arctic ground squirrel near Toolik Lake. / Image University of Alaska Anchorage

Professor Loren Buck releases an arctic ground squirrel near Toolik Lake. / Image University of Alaska Anchorage

Now, what about that cheating? Some of the squirrels are kept in the dark in the lab, not unlike what they would experience in their underground arctic burrows. Professor Buck explains, “Animals can cue into all the different things in their environment. Light is the most potent cue for most vertebrates, but feeding and exercise is another thing.”

When Brady cares for the squirrels on that random schedule, he dons night vision goggles, which, in addition to significantly upping his cool factor, allows him to protect the integrity of his research into the effects of light on the animals’ circadian rhythms. “Sometimes he’s feeding them at night, sometimes at seven in the morning. He’s here seven days a week maintaining the animals, downloading his data,” says Professor Buck.

A “vacation” in the Arctic Circle

Student Brady Salli peers into the cage of a hibernating arctic ground squirrel in a research lab in the Integrated Sciences Building at the University of Alaska Anchorage. Salli is working with professor Loren Buck and postdoctoral fellow Cory Williams to study arctic ground squirrels. / Image Erin Hooley, University of Alaska Anchorage Office of Advancement

Student Brady Salli peers into the cage of a hibernating arctic ground squirrel in a research lab in the Integrated Sciences Building at the University of Alaska Anchorage. Salli is working with professor Loren Buck and postdoctoral fellow Cory Williams to study arctic ground squirrels. / Image Erin Hooley, University of Alaska Anchorage Office of Advancement

That seven-day-a-week schedule doesn’t leave a lot of time for vacations during Brady’s senior year of undergraduate study. “[Professor Buck] has tricked me into thinking I’m on vacation when I go to the field. Because I’m not here,” says a smiling Brady. “So I end up spending part of the summer, for instance, at Toolik Field Station.They’ve got all the gummy bears you can eat up there.” And more mosquitoes than you can shake a bug zapper at, but it’s free room and board, provided you spend those daylight hours (read: the ones during which you are not sleeping) engaged with the research project.

Brady is just one trusted member of Professor Buck’s research team that also includes Cory Williams, a post-doctoral fellow and the man in charge of getting the whole team geared up for a summer of arctic ground squirrel study based at Toolik Field Station, a research facility run by the University of Alaska Fairbanks (UAF) Institute of Arctic Biology. The facility is primarily frequented by climate scientists from around the world. What’s great about that is, “It puts our animals in a very well- described context,” says Professor Buck.

Post-doctoral fellow Cory Williams, co-principal investigator on the grant, holding a hibernating arctic ground squirrel. / Image Erin Hooley, University of Alaska Anchorage Office of Advancement

Post-doctoral fellow Cory Williams, co-principal investigator on the grant, holding a hibernating arctic ground squirrel. / Image Erin Hooley, University of Alaska Anchorage Office of Advancement

Awarded in August 2012, the team’s NSF grant of $1.6 million over four years will fund research at three universities, with UAA as the lead university. At UAA, Professor Buck and Cory, who is a co-principal investigator (co-PI) for the project along with Buck, will oversee a still-growing arctic ground squirrel research team, including Brady.They’ll also work with Brian Barnes, their UAF co-PI, as well as a significant collaborator from Michigan State University, who will act as their gene expression exper t.The team will spend summers in the field, beginning in 2013, and the rest of each year conducting lab-based research with captive animals.They hope to be joined by an NSF PolarTREC teacher, too, who would accompany them to the field for a few weeks as a sort of “embedded” K-12 science teacher, blogging, taking photos and developing lesson plans for younger students based on the team’s research.

Equipped for research

The research team’s base of operations on UAA’s campus is the ConocoPhillips Integrated Science Building, which was completed in 2009. If you want a precise date, just ask Professor Buck, who remembers it distinctly.

“It was completed on Aug. 2, 2009. I moved animals in on Aug. 2, 2009,” he says with a laugh. “Within a year of moving in we were at 80 percent capacity. We went from zero captive animal research in biological sciences to 80 percent capacity in a year. It really speaks to the need that we had for a facility like this to do research.”

One element of the vivarium that enables sophisticated arctic animal research is the cold rooms, where they’re able to simulate winter burrow
conditions for the squirrels. “Getting these cold rooms gives us amazing capacity. Not many places in the world have the ability to keep animals at minus 50. Not many species in the world can tolerate those extreme temperatures beyond the animals that live up here.”

And these squirrels are some of Alaska’s hardier animals—the little guys drop their core body temperature below freezing during hibernation and snooze in burrows that can reach 40 below (Celsius) while maintaining body temps as low as minus 3 degrees. Makes you want to add another down comforter to your bed, doesn’t it?

Life in the lab

Cory comes to this most recent grant-funded research project as a long-time member of Professor Buck’s laboratory. He pursued a doctorate under Professor Buck when he was at UAF, conducted sea bird research with him at a field station on Kodiak Island as a Ph.D. candidate and worked as a post-doctoral fellow with both UAF and UAA to analyze long-term body temperature data sets and gene expression data. “We used that [pilot data] to demonstrate that [arctic ground squirrels] have this very tightly regulated circadian rhythm and that it persists throughout the summer,” he says. Up for debate is whether that rhythm persists during hibernation.The team thinks not, but hypothesizes that the rhythm is jump-started with a light cue each spring.

Student Brady Salli holds a hibernating golden mantle squirrel. / Image Erin Hooley, University of Alaska Anchorage Office of Advancement

Student Brady Salli holds a hibernating golden mantle squirrel. / Image Erin Hooley, University of Alaska Anchorage Office of Advancement

Brady has also been a researcher with Professor Buck on other projects in the past. (“I set the hooks deep,” says Professor Buck.) He doggedly pursued research oppor tunities as a freshman and has been engaged suppor ting Professor Buck’s research and conducting his own research for almost four years. Professor Buck notes that Brady has applied for and won ever y major grant competition available to students at UAA, including
a Chancellor’s Award, a College of Ar ts and Sciences Award and an Alaska Heart Institute fellowship.

“Brady is doing graduate-level work and has graduate-level responsibilities now,” says Professor Buck. He’s looking forward to Brady’s official step from trail-blazing undergraduate to graduate student, hopefully next year.

“When an undergrad is brought in [to work in the lab], they’re usually handed off to a grad student who then just makes them clean glassware or something,” says Brady. “From the get go [Loren] made clear that there’s the evil necessary part of doing the husbandry and cleaning stuff, but at the same time, you’re at school to learn a new career so you need to start doing that.”

What does it cost to be out of sync with the environment?

Professor Loren Buck with researchers near Toolik Lake. / Image University of Alaska Anchorage

Professor Loren Buck with researchers near Toolik Lake. / Image University of Alaska Anchorage

Building on Cory’s pilot data that indicated arctic ground squirrels keep to a regimented schedule, the team is beginning phase two of their research. Beginning this summer, they will take a look to see how circadian rhythms are exhibited among a free-living population of squirrels near Toolik Lake.

Professor Buck explains, “There’s a circadian clock that regulates your day-to-day activities—when you get up in the morning, when you get hungry, those sorts of things. But there’s also a circannual clock and we don’t know where that is or how that molecular clockwork functions, but we know it exists, just by existence of this seasonal rhythm—when to start hibernation, when to end hibernation, when to reproduce, when to get fat for hibernation, those sorts of activities.”

Night vision goggle view of an arctic ground squirrel. Collecting data for light-sensitive experiments means Brady Salli is adept at navigating the lab in the dark. / Image Erin Hooley, University of Alaska Anchorage Office of Advancement

Night vision goggle view of an arctic ground squirrel. Collecting data for light-sensitive experiments means Brady Salli is adept at navigating the lab in the dark. / Image Erin Hooley, University of Alaska Anchorage Office of Advancement

They’ll determine if those first glimmers of spring light “reset” internal clocks and if the animals are sensitive to changes in light quality and intensity. With their collaborator at Michigan State, they’ll find how clock gene expression shows up in the brain. And— this par t is pretty cool—they’ll “offset” a group of captive animals (so their “noon” is actually midnight) before they’re released at Toolik Field Station and track them to see if and how they realign themselves with geophysical time. With this “phase-shifting” experiment, Cor y says, “We’ll look at the metabolic cost of being out of sync with the environment.” How does being active during “subjective night” affect the animals?

“Theoretically, if you’re out of sync with your environment, this should prove that there is a cost,” Cory says.To gather the data they need, the team will use light loggers that indicate when the animals are above and below ground, body temperature loggers to determine activity levels and telemeters to help them locate their subjects so they can periodically measure their metabolic rate.

But what does it all mean? Right place, right time.

UAA is taking advantage of the assets we have in place, including intelligent and savvy researchers, state-of-the-art facilities and proximity to unique subjects, to establish ourselves as leaders in Alaska scientific research. Funding for research is competitive, par ticularly in light of a down economy. Funding rates right now are hovering between four and six percent, which means more than 90 percent of all grant applications get scuttled. Professor Buck is helping to create a sustainable infrastructure of scientists and science study at UAA that will continue to be competitive.

Professor Buck in the field. / Image University of Alaska Anchorage

Professor Buck in the field. / Image University of Alaska Anchorage

“[This project] is a good example of place-based research,” says Professor Buck. “We have a unique ability here to access arctic animals and study them in the wild. And then we have facilities in the state that are specifically designed to hold arctic animals and do manipulations. So we can bounce ideas back and forth.”

Through a combination of lab and field work, the team will answer the questions they’ve posed. “Just because something works in the lab, doesn’t mean that’s how it works in the field. So you come up with an idea in the field and come back to the lab, control ever ything but that one thing and see if you get the same answer. Often you don’t,” says Professor Buck.

It’s those differing answers that drive spin-off projects for some of the students involved with a project. Professor Buck encourages students, like Brady, to develop their own complementary projects while still meeting the objectives of the faculty research they’re suppor ting. By encouraging independence, fostering curiosity and providing that hands-on experience, he’s developing the future generations of biologists in Alaska and beyond.

Animal husbandry tasks in the vivarium fall to undergraduate student workers who learn proper care and handling techniques and, like Brady Salli, can work their way up to managing their own research projects in conjunction with their faculty research duties. Lab experience also gives students applying to graduate school a leg up. / Image Erin Hooley, University of Alaska Anchorage Office of Advancement

Animal husbandry tasks in the vivarium fall to undergraduate student workers who learn proper care and handling techniques and, like Brady Salli, can work their way up to managing their own research projects in conjunction with their faculty research duties. Lab experience also gives students applying to graduate school a leg up. / Image Erin Hooley, University of Alaska Anchorage Office of Advancement

When you ask Brady where he’s headed after graduation, he smiles and says, “Probably here for more squirrel stuff.” While he talks, he’s multitasking— handling animals and fielding questions from other researchers in the lab. “It would be a real bummer for someone to spend their entire undergrad learning about something and then when they go to do it, they find out they hate it. I know I want to do this because I am doing it.”

Jamie Gonzales

University of Alaska Anchorage Green & Gold News

"Arctic ground squirrel chronobiology; Wake up, guys, my biological clock says it’s…spring?" original post (Creative Commons Attribution 4.0 International License) url: http://greenandgold.uaa.alaska.edu/blog/10463/arctic_ground_squirrel_chronobiology_wake_up_guys_my_biological_clock_says_itsspring/

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