Every summer, 20 undergraduates from around Maine and the nation embed in the research groups of MDI Bio Lab’s seaside campus, for a 10-week scientific adventure alongside world-class faculty mentors.

They gain firsthand training in advanced lab procedures, improve their critical thinking skills, and explore opportunities for professional development (while being paid for the valuable work that they do).

Sometimes, their work advances science itself.

That’s what 2023 SURF program Summer Fellows Abigail Wick and Taylor Stephens achieved this year, when they made a new discovery about how exposure to the stress hormone cortisol affects development of zebrafish.

Zebrafish are one of the unique array of models for human health that MDI Bio Lab specializes in, and cortisol is a steroidal hormone that increases in response to stress. Scientists in the laboratory of James Coffman, Ph.D. use cortisol treatment to examine whether some of the persistent adverse health effects of early life stress are caused by elevated cortisol.

But until this summer no one  knew the precise timeframe of development in which exposure to cortisol produces those effects.

“It’s kind of the standard in the Coffman Lab to expose the zebrafish larva to cortisol, just in their environment, for the full five days of their development,” Stephens says. “So, the question that Abigail and I were asking was, ‘does it have to be five days?’ ”

To answer the question, the students went through something of a crash course in benchwork. Stephens says it proved to be harder than she had imagined at the outset.

“The first day our lab mentor Janelle (Grendler) said to us ‘can you guys pipette micro-amounts of a treatment and we both said ‘yeah, we’ve definitely done that, we can do that,’ ” she recalls. “But then it came time to load a plate with samples of larvae… the plate had 384 wells. I had never seen a 384-well plate in person before. Those wells are tiny!”

The project required weeks of trials, retrials, and caused some hand-cramps along the way, but it ended in success. The zebrafish were genetically programmed to produce fluorescence when the stress response is triggered, and the young women used that signal to pinpoint the minimal effective timing for cortisol applications.

They found that cortisol only needs to be applied from the fourth to fifth day of the fish’s development to produce a response. The work demonstrated that the developmental processes affected  by the cortisol treatment are not active in the first three days of development – a meaningful research result.

And at a very practical level, it means research in this area at MDI Bio Lab and elsewhere can dispense with cortisol treatments for the first three days of development – an important finding for laboratory efficiency.

“Taylor and Abby discovered that the developmental window of vulnerability to the cortisol exposure is relatively late, encompassing a stage after which much of larval development is complete, but continues in the central nervous system,” says James Coffman, Ph.D., the Principal Investigator (PI) who is leading research here on the effects that early stress exposure can have on physical and cognitive health later in life – work that will inform efforts to reduce harmful stress effects in humans. “They worked well together and made a great team, and it was a joy to have them in the lab.”

Wick is now a junior at Colby College, Stephens a senior at Mississippi College. They say that their experience in Coffman’s lab built a storehouse of knowledge, skills and confidence that will propel their careers in biomedical science: Taylor intends to seek a Ph.D. in neuroscience; Wick says she will seek a medical degree.

“You obtain so many skills with the PIs and their lab partners, whether it be data analysis, or science communication, or critical thinking and how best to work through an experiment,” Wick says. “And in addition to that, you’re in such a beautiful location with an amazing cohort of other people that have very similar career goals to you — the networking you’re able to have while you’re at MDI is incredibly valuable. So… highly recommend.”

Applications for the 2024 SURF program are due by January 26th! Find out more here.