Zebrafish amazed Colleen Carpenter-Swanson when she learned about their scientific potential from her pharmacology postdoc mentor at the University of California, San Francisco. At the time, her labwork involved using mice for addiction research.

“He was studying epilepsy in zebrafish, so that was my first exposure to the field,” the biology professor said. “I hadn’t really seen the translational aspect until then.”

She gleaned that the blue-striped tropical fish have many similarities to humans, and their complicated circuitry makes them a surprisingly good model for probing brain disorders. They’re also far more cost-effective than rodents: One female adult zebrafish can produce as many as 200 embryos at a time.

“I was used to working with four mice, if I’m lucky, in an experiment,” Carpenter-Swanson recalled. “All of a sudden you’re telling me I have 100 embryos to test my questions on?”

The big question in her UR lab now centers on how to treat a particularly severe early-onset epilepsy. Around 1% of the U.S. population has epilepsy. A rarer epilepsy type linked to mutations in the gene syntaxin-binding protein 1—STXBP1 for short—affects an estimated one in 30,000 and causes frequent spontaneous seizures.

“We’ve had beautiful experiments done in the past that have found some of the anti-epileptics we use today,” Carpenter-Swanson said. But a third to half the epilepsy patients taking available drugs don’t respond well to them, she added. Some treatments can even produce highly adverse side effects, such as childhood developmental delays. Some medications don’t work at all.

She said that her research goal is to learn how to treat the disorder and not cause harm.

During an epileptic seizure, the brain lights up with abnormal electrical activity. That’s where the zebrafish come in. Carpenter-Swanson and her students use the fish to screen FDA-approved drugs for potentially treating STXBP1.

“We already know the safety profile of these drugs,” she explained. “The hope is that we find this new indication.”

UR students learn how to perform the experiments, optimize them, and develop new ones. If they can identify compounds that block seizures in the zebrafish model, the existing drug could be repurposed for STXBP1 patients. Recently, the STXBP1 Foundation awarded Carpenter-Swanson a $25,000 seed grant to support this novel research.

These efforts further prove that the zebrafish model has broader scientific applications than previously imagined. “The more successful experiments we produce, the more we show that zebrafish belong in the `benchtop to bedside' model," she said.