News Archive 2009-2018

Studying Goldfish Brains to Better Understand Hormone-Behavior Link Archives


Julia Gomez ’15

Since arriving at Bowdoin last year, Julia Gomez ’15 has become an expert on the social natures of goldfish, as well as a kind of ichthyo-neurosurgeon.

Within days of arriving at Bowdoin, Gomez was invited to work in the lab of Rick Thompson, professor of psychology and neuroscience and the director of Bowdoin’s neuroscience program. Since then, she has been studying goldfish to pinpoint where and how estradiol, a type of estrogen, acts in the brain and how this hormone affects the interest male goldfish take in their female counterparts.

“We’re looking at how hormones influence behavior, particularly in a social context,” Gomez explained. Based on the results of her research, Thompson said he hopes to co-publish a paper with Gomez next year.

Experiencing Science at Bowdoin
Last August, Julia Gomez ’15 participated in the Bowdoin Science Experience, a week-long program designed to introduce first years – particularly students of color, women and first-generation college students – to Bowdoin’s science and math community. During this week, Gomez met Neuroscience Professor Rick Thompson, and gained a position as a research assistant in his lab.

Gomez, who was a BSE mentor this August for incoming first-year students, credits BSE with giving her a strong start at Bowdoin. “BSE helped get me into research right away by placing me into a lab during my first semester,” she said.

This summer, Gomez continued her experiments on goldfish, funded by a Kibbe Fellowship, which supports faculty and student science research at Bowdoin.

So far Gomez’s work has produced intriguing results.

Typically estradiol passes through a cell membrane to move into the nucleus and influence gene expression. Over hours or days, this action makes a behavior more or less likely, Gomez explained.

But the hypothesis behind her research is that rather than passing through a cell membrane, estradiol binds to a receptor on a cell membrane in the brain’s visual processing area. This triggers rapid changes inside the cell, making it likely the goldfish will exhibit changes in behavior within minutes. So while estradiol can use both processes, scientists are now gaining greater understanding of how the rapid mechanism influences behavior.

Specifically, Gomez was looking at the behavior of male fish toward females within 20 minutes of being infused with estradiol. She found that male goldfish spent more time swimming close to females when estradiol – by itself or when conjugated to a protein that keeps the steroid from passing through cell membranes – was infused into their brains. And the males spent less time by the females when no steroids were infused. These findings support the theory that estradiol is using a membrane receptor to mediate quick effects on behavior.

Estrogen is a type of steroid, and Thompson said the work Gomez has done helps illuminate “a new way of thinking how steroids affect behavior in vertebrates.”

To do the kind of research, Gomez has become a kind of neurosurgeon. To conduct her experiments, she had to insert a cannula into the brains of about 40 live male fish to inject the estradiol.

Photo by Lisa Mangiamele

Thompson gave Gomez credit for mastering a delicate surgical technique on a small creature. “It’s a tough surgery that she spent a lot of time learning to do,” he said. Thompson’s postdoctoral research associate Lisa Mangiamele taught Gomez the procedure. Gomez said she ate with chopsticks for weeks to accustom her hands to precise motions.

Gomez will continue her research in an independent study this year with funding from the National Science Foundation. “She’ll continue the work with follow-up experiments to learn more about the receptor that’s mediating the estrogen,” Thompson explained.

Gomez said she has appreciated the chance to do publishable scientific work so early in her college career. “A great part of Bowdoin is that as an undergraduate, you can do research,” she said. “Ultimately this is a really great way to learn and supplement lectures.”

This spring, Gomez said she plans to declare a neuroscience major. Although at the moment she’s torn between practicing medicine and doing research, she’s certain she wants to continue in the field of neuroscience, she said.