First year SEAS graduate student Adam Dionne is a 2022 LeRoy Apker Awardee for his undergraduate research in active fluid transport networks within a slime mold. Only two Apker awards, supported by the American Physical Society, are given out each year to undergraduates who have displayed excellence in research and the potential for future scientific accomplishment. Each recipient is awarded $5 thousand and is invited to present their work at a future APS meeting.
Dionne graduated from Williams College in Spring ’22 and has begun his graduate work at Harvard in the lab of Maxim Prigozhin, studying the dynamics of transmembrane signaling.
“Almost all biological life bigger than a single cell utilizes fluid transport networks,” says Dionne, of the undergraduate work that earned him the award. “Humans have our blood to transport oxygen and nutrients, which is organized by our heart, a central pump. Some organisms instead use a decentralized process in which local pumps coordinate behavior. I wanted to know how these systems self-organize to effectively transport nutrients.”
Dionne focused on the slime mold Physarum polycephalum, which creates a network of tubes to forage and transport nutrients. Each tube rhythmically contracts and expands to pump fluid, creating a spatial pattern within the slime mold based on each tube’s displacement from equilibrium. Dionne’s work decomposed these spatial patterns into basic modes—or fundamental physical representations of motion—that are easier to qualify. He was able to use this modal model to understand how the slime molds organize their fluid to transport without needing a centralized system. Since active fluid transport networks are found throughout biology, Dionne’s work has broad implications for understanding nutrient transport.
This work was Dionne’s first foray into biophysical research. As a math and physics double major at Williams, he had conducted research within the disciplines of graph theory and materials science, among others. But a thesis project posed by Professor Henrik Ronellenfitsch piqued his interest in the biophysical area.
“I thought Henrik’s work looked super interesting and took the risk to see if I would enjoy thinking about a biological system,” says Dionne. “And it turns out I really did.”
Now at Harvard in the Prigozhin lab, Dionne is working on understanding the dynamics of G protein coupled receptors, or GPCRs—proteins that allow cells to receive signals from their environment. The signaling processing is fast and the proteins are very small, and so it has been difficult to resolve GPCR dynamics with typical microscopy techniques.
“Max’s lab is trying to overcome this blind spot,” says Dionne. “We are validating a new biophysical tool that lets you cryo-vitrify cells—so freeze them really fast, basically—at ultrafast time delays after the signaling process begins.”
This technique has the researchers labeling the proteins with a fluorescent dye and stimulating cells with a drug that starts the cell signaling process responsible for our adrenaline response. They then essentially flash-freeze the cells at certain time points and image them with super resolution microscopy to assess how the proteins both organize themselves and execute their function.
“GPCRs are the targets of about 30 percent of all FDA approved drugs,” says Dionne. “They are incredibly important to our own physiology, and as such are common drug targets. There are a lot of applications to understanding the dynamics of transmembrane signaling.”
Dionne has been enjoying attending school in the lively and energetic Cambridge, a big change from the bucolic Berkshires setting of Williams. He is also thriving in the interdisciplinary atmosphere of the Prigozhin lab. The researchers Dionne works with come from backgrounds in everything from optics to bioengineering, making it an intellectually stimulating atmosphere.
“We’re really leveraging that diversity of background to solve a challenging problem that needs to be interdisciplinary because it touches on so many different topics and requires so much different expertise,” says Dionne.
The respect for interdisciplinarity made Dionne a perfect fit for the Prigozhin lab.
“I look for people who are creative and open-minded, people who are passionate about science but are also friendly and sharing,” says Prigozhin “Adam is a very promising young physicist. Very thoughtful and careful, which is rare to see at such an early career stage. In my group, Adam is building on his theory skills, while also supplementing them with the knowledge of biophysical instrumentation and measurement – a powerful combination of expertise that will allow Adam to address central questions in biophysics and, hopefully, serve as a launchpad for Adam’s future career in science.”
As of now, Dionne hopes to continue in academia once his doctorate is complete, preferably at a liberal arts university that puts equal emphasis on both teaching and research. Wherever he winds up, he hopes to make outreach and public education a centerpiece of his career.
“I love communicating about science,” he says. “It’s important for scientists to face the public and build up trust and open communication. In my career, I want to communicate scientific topics to a wide audience and lower the barrier to entry as much as possible.”
