CNN shines spotlight on groundbreaking UW-Oshkosh hibernation research offering clues to combat human cancer, heart disease

An adult 13-lined ground squirrel rests curled in its nest during torpor, a deep state of hibernation in which body temperature, heart rate and metabolism drop dramatically. UW-Oshkosh researchers study these natural survival mechanisms for insights into human health.

When CNN's Vital Signs explored how hibernating animals could hold clues to treating cancer, heart disease and even protecting astronauts in space, part of that story traced back to the University of Wisconsin-Oshkosh.

The episode highlighted cutting-edge biomedical research involving hibernating animals, but much of the foundational work behind those discoveries has been taking place quietly for decades at UW-Oshkosh , where faculty-led research, undergraduate training and a unique ground squirrel breeding program have created a resource used by scientists around the world. Watch the episode here.

A national story rooted in UWO research

The CNN segment followed researchers examining how hibernation allows animals to survive extreme physiological stress, including conditions that mirror heart attacks, hypothermia and cancer dormancy. One portion of the episode focused on cancer research led by University of Utah professor Christopher Gregg. While the segment did not dwell on where the underlying data originated, UW-Oshkosh has long provided ground squirrel tissue samples and data sets that support hibernation research, including Gregg's studies now informing cancer research.

The episode also featured footage from a specialized hibernation facility known as a hibernaculum, a controlled cold dark environment that allows animals to safely enter,cycle through and exit hibernation. That hibernaculum was developed through National Institutes of Health facility renovation funding at UW-Oshkosh and is central to the University's ability to study hibernation under carefully monitored conditions.

A unique research resource in UW-Oshkosh laboratories

The CNN segment also highlighted work by Fauna Bio, a biotechnology company that studies hibernating animals to unlock new approaches to medicine. Central to that work is a research resource at UW-Oshkosh: the world's first and only captive breeding program for 13-lined ground squirrels that reliably hibernate.

That breeding program has made UW-Oshkosh a hub for hibernation research, supporting studies spanning cancer, heart disease, neurological conditions and spaceflight. While the CNN story focused on its relevance to human health, the infrastructure that makes those discoveries possible has been built over more than two decades in Oshkosh.

That connection extends beyond research materials. Three UW-Oshkosh alumni now work for Fauna Bio as part of its Oshkosh-based research operations, all of whom trained in hibernation research on campus before launching their scientific careers.

Decades of faculty-led research

Dana Merriman, professor emerita of biology at UW-Oshkosh, began the ground squirrel research program more than 20 years ago. Initially focused on vision research, the program evolved into a nationally and internationally recognized resource for scientists studying vision, hibernation, metabolism and disease.

At a time when rats and mice dominated biomedical research, Merriman recognized that ground squirrels offered something different: a mammal with a human-like visual system and a natural ability to hibernate. Captive breeding, however, was widely considered impractical.

Through years of trial, refinement and close attention to animal welfare, Merriman and her students succeeded in building a stable breeding colony. That achievement transformed UW-Oshkosh into a hub for hibernation research and allowed scientists elsewhere to pursue questions that had previously been out of reach.

Over the years, Merriman's lab has supported researchers across the United States and internationally, including academic laboratories and industry partners such as Fauna Bio. Her work helped establish protocols that allowed hibernation research to move forward in controlled, ethical and reproducible ways.

Titan alumni on a national stage

UW-Oshkosh alumni Ryan Sprenger ('14, '16) and Benjamin Sajdak ('13) both appeared in the CNN segment as part of Fauna Bio's Oshkosh-based research team.

Sprenger, senior research physiologist and director of Fauna Bio's space programs, said seeing the work featured on a national platform was both surreal and affirming.

"A lot of work went into the work featured on the segment and it took a great team to do it, so I was quite happy to see it featured on such a stage," Sprenger said. "To have some of that work done at UWO made it all the more special too since that is where I started my career in research and hibernation."

Sajdak, director of research at Fauna Bio, said the CNN story would not exist without UW-Oshkosh.

"The institution's initial and continued support of Dr. Dana Merriman's ground squirrel research and colony is how any of this begins," Sajdak said. "It's decades of really hard work from Dr. Merriman, her students and many collaborators that brought us to where we are now, with a squirrel colony that has become an invaluable resource for the scientific community."

Why UW-Oshkosh matters to hibernation research

Sprenger said UW-Oshkosh's value lies not just in its history, but in what the squirrel colony makes possible today.

"UWO is the only breeding facility for squirrels that hibernate in the world right now," he said. "Observing the 'neat' things that hibernators do and showing that to the world is one thing, but taking those neat things and turning them into treatments for people is the real goal. That doesn't happen without the resources the UWO squirrel colony provides."

That access directly shapes his work at Fauna Bio.

"Take an example from my own work," Sprenger said. "We're studying hibernation in space to improve astronaut health, and that won't be possible without animals from the UWO facility where we can train the animals in preparation for space flight."

Sprenger earned his bachelor's degree in biology in 2014 and his master's degree in biology in 2016 at UW-Oshkosh. During that time, he worked closely with biology professor Courtney Kurtz, whose mentorship played a key role in his development as a researcher.

That experience helped launch Sprenger into doctoral training and international research opportunities before he joined Fauna Bio in 2023.

Sajdak credits UW-Oshkosh with shaping not just his technical skills, but the way he approaches scientific questions.

"UW-Oshkosh taught me how to think," Sajdak said. "I started with vague interests in writing, reading and science. Courses in writing, philosophy, psychology and biology turned those interests into a passion for lifelong learning."

He earned a Bachelor of Science in biology with a minor in neuroscience from UW-Oshkosh in 2013 and was a McNair Scholar and undergraduate researcher.

"My time in the McNair Scholars Program showed me what is possible after graduation," Sajdak said. "And my lab experience built the foundation for the skills needed to become a career scientific researcher."

Learning to 'speak squirrel'

Merriman said she was not surprised when Fauna Bio hired UW-Oshkosh alumni to staff its Oshkosh-based lab.

"They spoke fluent squirrel, and this was the squirrel home base," Merriman said.

The phrase reflects more than technical expertise. It describes the deep understanding of the animals' biology, physiology and behavior that students develop through hands-on research and long-term care.

For Merriman, the visibility from CNN captures only a fraction of what has grown out of the UW-Oshkosh program.

"There's a much longer list of accomplishments that could have been featured that started with Oshkosh squirrels," she said. "You'd have to have like a two-season series on Netflix to get all of it."

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