For the second summer in a row, Ian Thornell, PhD, assistant professor in Pulmonary, Critical Care and Occupational Medicine, took his expertise 1,243 miles northeast to MDI Biological Laboratory in Bar Harbor, Maine.
Surrounded by the granite peaks and rocky beaches of Acadia National Park, this historic lab hosts the Kidney TREKS [Tutored Research & Education for Kidney Scholars] research course. The program enables medical students interested in nephrology and renal medicine to closely examine key kidney functions through a series of modules, each focused on a specific physiological concept.
The course’s acid-base module—a crucial component for engaging students in the kidneys’ pH-balancing mechanisms—was discontinued for a few years following the COVID-19 outbreak. That is, until Thornell’s Mayo Clinic colleague and MDI Lab Kidney Stone Module Director, Michael Romero, PhD, connected him with TREKS’ Course Director Mark Zeidel, MD. Thornell credits Zeidel’s leadership and enthusiasm as pivotal to his re-creation and facilitation of the module.
TREKS immersive lab experience
Thornell designed his curriculum to incorporate three days’ worth of experiments related to cellular and renal acid-base homeostasis. The module opened with a cellular focus, where students measured and experimented with altering the pH of the tubules of flies while observing the changes through microscopes.
“The fly is like a homage to the course itself,” Thornell said. “Mount Desert Island has always been this lab where you find a creature that does something really well, and then you study it. It’s using a lower organism to understand something about human physiology, which has always been a big theme of the lab.”
Thornell departed from this theme at the end of his module when students and faculty served as experimental subjects. A homeostasis experiment facilitated by Thornell involved attendees breathing into capnometers to measure carbon dioxide, a form of acid that people expel through exhalation. Students performed this standing still and then running up and down stairs, using their data to determine how movement and exercise intensity influence acid clearing.
TREKS learners remained the experimental subjects in another experiential session led by Thornell. To determine how much citrate they would have to ingest to increase their body’s pH, a group of students drank a few ounces of sodium citrate water while a control group drank an equivalent amount of sodium chloride. Students then measured the pH of their urine hourly over the next four hours. The citrate group watched their urine pH spike to 7.75 as their kidneys excreted the excess base before returning to baseline.
Thornell says it is engaging for students to observe their bodies undergoing pH regulatory mechanisms as they learn about physiology. These hands-on experiences also emphasize Kidney TREKS’ mission and purpose.
“The time students spend with basic science has dwindled down into a smaller time frame. A lot of teaching comes from undergrad, then it’s off to the races,” Thornell said. “This course was designed to give people who are interested in renal physiology or nephrology a chance to dive deeper into concepts and do the laboratory experiments that led to the findings in some of what they’d read in medical textbooks.”
As Thornell facilitated enriching pedagogy for medical students, he also embraced the schedule’s opportunities to bond with TREKS attendees. Students and faculty enjoyed hiking and kayaking through Acadia National Park every afternoon following module instruction. Thornell says the opportunities to build connections through both laboratory work and non-instructional time alike make TREKS an especially worthwhile course.
“There is a lot of bonding between faculty. The students get really close faculty time, and because it’s a selective national course, you really get to see the best of the best in nephrology and renal research,” he said.
Iowa’s Mount Desert Island legacy
Thornell is not the first IntMed faculty member to work at the historic lab. Director of Pappajohn Biomedical Institute Michael Welsh, MD, studied the mechanism of Cl– secretion at MDI—work that is foundational to Thornell’s current research.
IntMed’s connections to MDI can even be traced back to the 80s. John Stokes, MD, once division director for Nephrology and Hypertension, conducted research that directed the course of Thornell’s current study of how pulmonary ionocytes contribute to Cl– absorption.
“We identified a chloride absorption pathway in pulmonary ionocytes that parallels work by John Stokes in the early 1980s. He studied chloride absorption in flounder bladder at MDIBL,” Thornell said. “His work laid the groundwork for understanding chloride transport mechanisms in the thick ascending limb of the nephron, which he studied here at Iowa. That foundational work directly shaped my current studies.”
UI faculty have certainly trekked Mount Desert Island. However, the TREKS program has not yet hosted a UI student, Thornell said. Medical students and fellows can submit a TREKS application for a chance to experience the immersive course and join Thornell in Maine for next summer’s session.
Although the 2026 course applications and session dates are not yet available, those who are interested in preparing to apply for a session can visit this page for more information.