As millions of Americans adjust their clocks for daylight saving time this week, many experience disruptions in their sleep and daily routines – a reminder of the importance of circadian rhythms that govern internal biological clocks. New research, led in part by Meet Zandawala, assistant professor of biochemistry and molecular biology at the ÍƼöÐÓ°ÉÔ´´, and his colleagues offer fresh insights into how these networks function, potentially paving the way for solutions to better manage circadian rhythm disruptions and the effects of time shifts like daylight saving time.
The team of international researchers, including Zandawala, has created the first comprehensive map of the circadian clock network in the fruit fly brain. This groundbreaking research, published in "Nature Communications," provides new insights into how the brain regulates sleep, metabolism and hormone release.
“This research advances science with real potential to address human health challenges," Bill Payne, dean of the College of Agriculture, Biotechnology & Natural Resources, said. “We’re proud to see our faculty leading discoveries with broad impact.”
The study was led by researchers from the ÍƼöÐÓ°ÉÔ´´ (United States), the University of Würzburg (Germany), and Okayama University (Japan), with Zandawala and Nils Reinhard, a doctoral student at the University of Würzburg, playing key roles in the discovery.
Every living organism, from insects to humans, operates on a 24-hour cycle, controlling vital functions such as sleep, hunger, metabolism and arousal. In vertebrates, including humans, this biological rhythm is governed by a master clock in the brain, located in the suprachiasmatic nucleus (SCN). However, because the human brain has about 20,000 clock neurons, understanding how they function has been a complex challenge.
“To tackle this complexity, we turn to model organisms like fruit flies,” Zandawala, who also conducts research as part of the College's Experiment Station unit, said. “With about 140,000 neurons, the fly brain is small enough to map but still complex enough to provide meaningful insights into how circadian rhythms are regulated.”
Advances in brain mapping enabled researchers to analyze the Drosophila connectome – a complete neural map. The FlyWire consortium, a global collaboration of 146 labs, created this open-access resource, offering an unprecedented tool for studying neural networks.
“This research expands our understanding of how the brain controls daily cycles and provides a foundation for studying circadian rhythm disorders in humans,” Zandawala said.
Using the newly available fly brain connectome, Zandawala and his team mapped the fruit fly's entire circadian clock network. Their research revealed about 240 neurons involved in timekeeping, a significant increase from previous estimates of 150. Now that the full clock network has been mapped, researchers can trace these pathways to determine how different brain regions process time signals.
“This study provides a detailed framework to understand the brain’s internal clock and how it impacts key functions,” Zandawala said. “Our findings could ultimately inform future treatments for sleep and metabolic disorders.”
Circadian rhythms regulate nearly every aspect of health – from sleep and metabolism to hormone production and mental well-being. Disruptions in these rhythms are linked to conditions such as insomnia, obesity, diabetes and depression. Future studies will explore how the clock network influences key behaviors, including feeding, locomotion and reproduction.
