A neuroscientist and assistant professor at the University of Alberta presented his research on the neural mechanisms of sleeping fruit flies at a Georgetown University biology department seminar Feb. 19.
Jacob Berry’s lecture — hosted by Isaac Cervantes-Sandoval, assistant professor in the biology department — was the latest in the department’s weekly invited speaker series and highlighted how specific brain circuits and chemical signals regulate when animals sleep and wake. Berry’s findings suggest that even in simple organisms, sleep is controlled by precise neural pathways, offering insights that could eventually help scientists understand sleep disorders and brain function in humans.
Cervantes-Sandoval, who introduced Berry at the event, emphasized the impact of his colleague’s work on the neuroscience field. He said Berry’s past research has reshaped scientific understanding of how brain circuits influence behavior.
“He found that the same neurons that are in charge of encoding memories are also involved in eroding these memories in the forgetting process,” Cervantes-Sandoval said at the event. “That paper kind of became a classic in the field.”
Sleep is essential for survival across species, affecting everything from metabolism to memory. Berry’s lab in Alberta studies how brain circuits regulate sleep and how those systems overlap with mechanisms for learning.
Berry explained that his team focuses on identifying how specific neurons and chemical signals control sleep and wakefulness. He said understanding these mechanisms requires studying the brain at multiple levels, from behavior to molecular interactions.
“We ask questions about how sleep is being regulated at molecular and circuit levels,” Berry said at the event. “Sleep is very important for maintaining functionality across the board.”
Berry’s research uses drosophila melanogaster, a species of fruit flies that is a common model organism in neuroscience. Although they are tiny, fruit flies display sleep patterns similar to humans, including sleeping at night and experiencing a midday rest period.
Berry said his lab discovered that different types of sleep in fruit flies are controlled by separate brain circuits. In particular, his team found that daytime sleep appears to depend on light and specific dopamine-related signaling pathways.
“Our working model is that light and daytime together are influencing dopamine signaling,” Berry said. “That signaling affects these neurons to promote wakefulness.”
His team also identified a receptor called “R2” that plays a key role in keeping flies awake during the day. When the receptor was removed, flies slept more, suggesting that dopamine signaling helps regulate alertness.
Berry said these findings challenge previous assumptions about how sleep circuits function.
“To me, that suggests that this circuit output was actually driving wakefulness,” Berry said.
Peter Kann (GRD ’28), a second-year doctoral student at Georgetown’s Weiss lab, which designs genetic circuits to better understand and control how cells behave, attended the seminar and said the talk revealed how sleep is more complex than it appears.
“Fruit flies sleep at night, but they also take a midday nap, and it seems that daytime and nighttime sleeping are controlled in part by different neural circuitry,” Kann said. “From an ecological perspective, I would think that it makes sense that the nature of sleep itself can also differ.”
Scientists have long known that sleep is critical for health, but its biological purpose and regulation remain active areas of research. Berry said sleep plays a fundamental role in keeping organisms functioning properly at every level.
“Sleep is very important for maintaining the functionality across the board,” Berry said at the event. “Everything from metabolism and immune system all the way to brain functions like emotional regulation, learning and memory.”
Kann said this research could have broader implications beyond fruit flies, and that by studying how simple brains control sleep, scientists can uncover insights that could ultimately improve human health.
“Understanding how sleep works from a mechanistic level, and what factors promote or prevent it, helps us understand why we need it and what might be going on in people with disorders that disrupt their ability to sleep,” Kann said.
