When she was a sophomore in high school, University of Oregon senior Tapley Sorenson was delighted by reading “The Tale of the Dueling Neurosurgeons,” by Sam Kean. This initial interest in neuroscience stayed with her as she came to college. Feeling slightly overwhelmed by the idea of committing to a major, she says choosing neuroscience was perfect for her because of how interdisciplinary it is.
“It felt like the best of all the worlds. Coupled with my Spanish minor and the Honors College curriculum it felt like I was getting all the holistic stuff that I wanted from my education,” said Sorenson.
As a senior Honors College student, Sorenson is currently working on her thesis project, which, as is the case for many students, involves working in an on-campus lab. She is part of the McCormick Lab, run by Professor of Biology and Neuroscience David McCormick. Her project evaluates noradrenaline’s contributions across the sleep-wake cycle, while also trying to identify any potential differences in patterns of activity by biological sex.
Noradrenaline is a neurotransmitter, which is responsible for regulating mood, attention, arousal, and our overall reactions to stress during waking hours. Sorenson’s project instead focuses on the role noradrenaline may play related to sleep, and different sleep states, such as rapid eye movement (REM) and non-REM. The McCormick Lab previously published a study that took on the waking perspective, looking at the activity of noradrenaline during wakefulness.
“We were looking at a particular cell type in the cortex during awake standard mouse behavior and we’re applying some of the same methodologies we’ve already used to study the brain during wakefulness to the sleeping brain as well,” said Kevin Zumwalt, the lab manager of the McCormick lab who is helping oversee Sorenson’s project.
Why This Research Matters
Although wild mice are nocturnal, the majority of mice used in research are housed in reverse light cycle rooms so that they will be awake during the day. As Sorenson’s project focuses on sleep, she needs the mice to be asleep during the lab’s operating hours, so she is creating a sleep protocol.
“What Tapley is currently working on is developing a sleep protocol in our lab to get our animals to fall asleep while they are on our experimental recording rigs,” Zumwalt said.
Sorenson is focusing on biological sex because the hormonal differences between biologically male and female animals impact their sleep cycles.
“It’s been established that biologically female animals experience these systemic disruptions to their sleep during the high hormonal phase of the reproductive cycle, specifically impacting the amount of time spent in REM versus non-REM,” she said.
Sorenson hopes that her research will highlight how important biological sex is as a factor in research. Historically, most studies have primarily been conducted with male mice and a lot of funding opportunities don’t require researchers to use both sexes in their projects.
Additionally, the sleep protocol she is creating will open opportunities for the lab to do more projects focused on sleep states, as currently most of their work centers around waking states.
“When we think about diseases of brain state, things that come to mind for me are anything from narcolepsy, insomnia to schizoaffective disorder, ADHD,” Zumwalt said. “These are all disorders of brain state, so having a better grasp at how this neurotransmitter is working, both in the awake and the sleeping brain, is going to provide clarifying insights on how this may go awry with the disorder. You could imagine the next step after this is looking at an animal model of ADHD and how processing is disrupted.”
Zumwalt also said that the project could potentially motivate sex-specific interventions for diseases of brain state and interventions based on specific times during the reproductive cycle.
The Benefits of Summer Research Experiences
This past summer, Sorenson participated in the VPRI Undergraduate Fellowship, which enabled her to work in the lab full-time and develop the sleep protocol and methodology for her project. She says that the opportunity to do research full-time was a useful experience as she’s interested in earning a doctorate and continuing in research after finishing her undergraduate degree.
“In the summer, there are a lot of people working in the labs, so the work environment is very collaborative,” said Sorenson.
Zumwalt agrees that collaboration in science is beneficial for research, especially for undergraduates who are learning a plethora of new skills in lab environments. While the majority of Sorenson’s work is done independently, she is working with McCormick and Zumwalt and receiving mentorship from other post-doctoral scholars and graduate students in the lab.
Sorenson hopes that her research will not only show the importance of accurately representing biological sexes in research but will also contribute to people’s overall understanding of sleep states.
“I’m very interested in how we can bridge the gap between researchers’ understanding of science and communication to the public,” she said.
— By Stephanie Metzger, Office of the Vice President for Research and Innovation