This Saturday, March 29, Harvard PhD candidate Mara Casebeer, a student in Daniel Needleman’s MCB and Applied Physics lab, will give a public Science Spotlights talk at the Harvard Museum of Natural History as part of the Science Education Partnership. The event, which is open to museum visitors, is designed to make scientific research accessible and engaging for a general audience. Casebeer’s talk, Highways and Cars in Your Brain, will explore neuron growth and the role of microtubule dynamics and motor proteins that shape the structure and function of these essential cells.
“My goal is to get people excited about science more generally,” Casebeer explains. “I won’t be focusing so much on my specific experiments, but rather introducing neurons, explaining why the things I study inside of them are interesting, and helping people appreciate the bigger picture.” Mara Casebeer will present her talk between 2PM-3:30PM at the Museum at 26 Oxford Street, Cambridge on March 29.
A Pathway from Physics to Biology
Casebeer, now in her third year as a PhD candidate in the Harvard Biophysics Program, has taken an interdisciplinary approach to understanding complex biological systems. Though she was drawn to biology from an early age—fascinated by nature and insects—she found herself more captivated by physics when she began studying it in high school.
“I took my first physics class, and I absolutely loved it,” she recalls. “We had this activity where we rolled a ball down a ramp and had to calculate exactly where it would land. When the ball landed perfectly in the cup, I was like, ‘Whoa. Physics is real. Physics works.’”
This realization led her to explore the intersection of physics and biology, where she found biophysics to be a natural fit. Casebeer studied at UC San Diego, earning her undergraduate degree in 2022 in biophysics. She then completed a brief internship at a major pharmaceutical company before joining Harvard’s Biophysics Graduate Program in September 2022, where she could use physical principles to unravel the complexities of biological processes.
Researching Microtubule Dynamics in Neurons
As a PhD student, Casebeer works in Needleman’s lab, which is affiliated with both MCB and Applied Physics. “Mara is a very talented and creative scientist, and it has been really wonderful having her in the lab,” Needleman says. His group combines approaches from physics and biology to try to obtain a quantitative understanding of biological systems. The team works on several areas, including studying cell division, cell metabolism, the nucleus, oocytes, and early embryos.
“While I have long found neurons fascinating – particularly how they obtain their beautiful, extended structures – my lab had not worked neurons until Mara joined the lab,” Needleman adds. “I have been very impressed with how much progress Mara has made in establishing novel approaches to study the biophysics of neuronal development and internal organization in the short time she has been in the lab, particularly given how this is such a new area for us.” Needleman is pleased that postdoctoral fellow, Michael van der Naald, recently joined his lab in 2024, also to study neurons. “With Mike and Mara, we are now able to collaborate with researchers at the Flatiron Institute, the New York Structural Biology Center, and Princeton,” he adds.
Casebeer’s research specifically focuses on microtubule dynamics in neurons. Microtubules are structural components of cells that help shape neuron growth and development. “Neurons start as roughly spherical cells,” she explains. “As they develop, they grow protrusions, typically one of which becomes the axon, while the others become dendrites. These structures are functionally different—axons send signals, dendrites receive them—and they also differ in their microtubule organization.”
Her projects investigate the relationship between microtubule dynamics and neuron morphology. “There are experiments where if you locally stabilize microtubules, you can actually grow a second axon,” she says. “And if you destabilize them, a developing protrusion won’t become an axon at all. I’m working to understand these dynamics quantitatively and eventually develop a model that explains how microtubule behavior shapes neuron growth.”
A Passion for Teaching and Science Communication
Beyond her research, Casebeer is deeply committed to teaching and science communication. She has taught Harvard’s Chem 10 course, where students learn chemistry through hands-on projects, including building a spectrometer with Arduino, 3D-printed parts, and circuits.
“It’s one of my favorite courses to teach,” she says. “Not only do students learn chemistry, but they also pick up technical skills like programming and circuitry. It’s great to see them put everything together into a functional spectrometer.”
This passion for education is one reason she sees her future in academia. “I loved my brief experience in industry, but I know that I want teaching to be a central part of my career,” she says. “Undergraduate education is really important to me, and I want to continue combining research with mentorship.”
As she prepares for her upcoming public talk, Casebeer sees it as another opportunity to make science more accessible. “Programs like the Science Education Partnership are so valuable,” she says. “They allow researchers to step outside the lab and connect with people who might not normally think about neurons and microtubules but can still find them fascinating.”
Her talk at the Harvard Museum of Natural History will allow attendees to glimpse the intricate world of neuron growth through the lens of biophysics and share her enthusiasm for the field.
