New research to shed light on how the brain keeps time

Twice a year, millions of Canadians adjust their clocks by an hour. While the change may seem small, our brains don't always adapt as quickly. 

University of Calgary psychologist and circadian rhythm researcher Dr. Michael Antle, PhD, is working to better understand how the brain's internal clock responds to changes in schedules, sleep and daily routines. The research could help scientists outline the impacts of daylight saving time, jet lag, shift work and sleep disorders. Antle is one of 100 recipients of this year’s Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant. 

"Our biological clock needs to be synchronized to our 24-hour world," says Antle, a professor in the Department of Psychology in the Faculty of Arts. "While light is the main cue, other experiences such as eating and exercise can also adjust the timing of our clock."  

Looking beyond light 

For decades, researchers have known that light is the strongest signal influencing the body's circadian clock, which helps regulate sleep, hormones, metabolism and other essential functions. Antle's research focuses on what scientists' call "non-photic" cues, factors other than light that can also affect the brain's timing system.  

These cues include exercise, social interaction, food and arousal — the body's state of alertness. Through his new NSERC-funded project, Antle hopes to map the brain pathways that allow these experiences to reset the circadian clock, which regulates our natural, innate daily cycles in the body and mind. 

"Studying these non-photic cues not only helps us understand how the brain is wired to regulate these responses, but can also lead to novel treatments to help people with sleep and circadian problems," he says. 

Connection between daylight time and the body clock 

With the recent elimination of semi-annual clock changes in both Alberta and British Columbia, Antle says many people underestimate how strongly the body's internal clock is connected to natural daylight. 

"When we change our schedules by changing our clocks, we create a mismatch between our schedule and our biological clock," says Antle. "In the spring, we often talk about losing an hour of sleep, but it is actually much worse than that. It is forcing our brains and bodies to wake up an hour earlier than they want for many weeks." 

He says the body's clock continues to follow the solar day, even when society's schedules shift. 

"When we change our society clock that tells us when to go to work and school, our biological clock doesn't get the memo," says Antle. The result can be what researchers call "social jet lag," which can leave people feeling tired, less productive and, over time, negatively affect health and wellness. 

 "While the extra hour of light in the evening does facilitate more outdoor activities after work in the warmer months, it comes at the cost of delaying and shortening our sleep." 

Investigating a key sleep and wakefulness system 

A major focus of the project is orexin, a neurotransmitter that helps regulate wakefulness and alertness. Disruptions in the orexin system are linked to narcolepsy, a disorder that affects the brain's ability to control sleep and wake cycles.  

"The discovery of orexin's role in regulating sleep and wakefulness has led to the development of novel sleep aids," says Antle. "These drugs are often easier for people to tolerate and have fewer side effects." 

Using advanced neuroscience techniques, Antle and his team will investigate how orexin and other arousal-related pathways communicate with the circadian clock. The work could eventually help researchers identify new ways to support people living with insomnia, jet lag, shift work-related sleep disruption, and other circadian challenges. 

Building knowledge that could improve lives 

While the project is focused on fundamental discovery research, Antle says the long-term goal is clear. 

"The ultimate goal would be to develop new interventions to help people with sleep and circadian problems," he says. "Our work looking at how these arousal pathways impact the clock is really exciting because it gives us a whole host of novel targets for developing such treatments."  

By uncovering how the brain keeps time, Antle's research could help improve our understanding of one of the most universal aspects of human health: getting a good night's sleep.