Circadian Rhythm and Blues – USC News & Events


Growing up on the Italian island of Sardinia, Alessandra Porcu sometimes dreamed of becoming a forensic detective – solving murders and other crimes by analyzing DNA, like the detectives she’d seen on TV.

“I have this strong curiosity, I always want to ask questions,” says Porcu, who joined the University of South Carolina’s College of Pharmacy this summer as an assistant professor. “I also loved doing jigsaw puzzles, putting things together and seeing all the pieces come together.”

The detective fantasy naturally faded once she entered college, but the fascination with solving mysteries lingered. She eventually earned a Pharm D. degree from the University of Cagliari in her native Sardinia and a Ph.D. in Neuroscience from the University of Cagliari and the University of Basel in Switzerland, where she studied the pharmacology of cannabinoid receptors in the mood-regulating brain circuit.

But while her neuropharmacological research satisfied her curiosity for a while, she sought out a more challenging mystery. “I wanted to apply what I learned about neuropharmacology to something bigger, like understanding how the environment affects the brain and regulates mood.”

She found what she was looking for at the University of California at San Diego, in the Department of Psychiatry, where she was studying how stress affects circadian rhythms in reward-related areas of the brain that regulate mood. A Pathway to Independence Award from the National Institutes of Health funded two years of her postdoctoral research training in a technique called fiber photometry, which she used to study the effect of nocturnal blue light on circadian rhythm and neuroplasticity in anxiety disorders.

Now, Porcu has brought her research interests—and her award, a three-year, $750,000 NIH grant—to the division for USC Drug Discovery & Biomedical Sciences, where she observed neuronal responses to blue light in the amygdala of growing mice at night.

The process involves attaching tiny fiber optic cables to the mice’s brains and then watching how neurons light up in response to various stimuli. It’s a painless procedure — “There are no pain receptors in the brain,” she says — but it has the potential to help develop new compounds to treat anxiety and inform the prevention of mental disorders in humans.

“I wanted to apply what I learned about neuropharmacology to something bigger, like understanding how the environment affects the brain and regulates mood.”

By understanding the mechanisms at work in the brains of mice, we could learn about how blue light, the light we are exposed to when we stare at our phones and other screens at night, circadian rhythms, and neuroplasticity in our own influences brains. She is also interested in how such light contributes to negative outcomes, particularly in adolescents.

“You can flash blue light at people, and with an fMRI, you can see brain regions that are activated,” she says. “A study showed that blue light activates the amygdala, which is the center of emotions. That’s why I study fear.”

In addition to exploring the potentially harmful effects of light on circadian rhythms, Porcu also hopes to improve our understanding of the relationship between circadian rhythms and the body’s positive and negative responses to various drugs.

“My idea is that if we understand how light affects our brain, we can improve drug pharmacology, since many protein receptors are controlled by circadian rhythms. If light affects these rhythms, light can affect the effectiveness of these drugs,” says Porcu. “For example, we can choose the best time of day to administer the drug.”

Porcu is excited about her lab’s potential contributions to mental health and chronopharmacology, but she’s not exactly a research junky. She’s also excited to teach at USC — and not just because she enjoys sharing her knowledge with students. Explaining the subject to students also helps her refine her own knowledge of a rapidly evolving subject.

“If you don’t understand something, try to teach it – because you have to go deep to simplify it,” she says. “Or as my favorite professor in Italy used to say, if you can’t explain it well, it means you didn’t understand it well yourself.”


Comments are closed.