AMHERST, Mass. – Michael A. Henson, a chemical engineer at the University of Massachusetts Amherst, is one of three researchers working with a four-year, $1.8 million grant from the National Institutes of Health to study circadian rhythms in an effort to better understand the workings of the human body clock.
The research could provide the basis for new forms of light or drug therapies that will allow people with changing work schedules to stay alert when awake for long periods of time and to avoid chronic fatigue from irregular sleep. He says this affects people such as shift workers, physicians, soldiers, airline pilots and nurses who often don’t have set work schedules.
The other researchers are Erik Herzog of Washington University and Yannis Kevrekidis of Princeton University.This grant, awarded in the fall of 2016, is a continuation of funding from two previous grants from the NIH, issued in 2006 and 2012.
The team will focus on the impact of shift work and how changing work hours upsets the internal body clock leading to constant fatigue, Henson says. They will conduct experiments on mice and will observe how shifting the light-dark cycle from day-to-day affects them.
Henson says the key to understanding the circadian rhythm, the 24-hour oscillation of biochemical, physiological, or behavioral processes in the human body, is the suprachiasmatic nucleus (SCN) region of the hypothalamus, in the brain stem. “This is the master time-keeper for the entire body,” Henson says. It is part of the brain where about 20,000 neurons synchronize with each other to create the circadian rhythm that helps control sleep patterns.
Those time-keeping neurons are influenced by external cues, especially daylight, and that information is sent to the brain stem via nerve fibers. He also notes that there are different kinds of neurons in the SCN region and they will be studying how they connect and organize as a group. “We’re tryin to understand how they exchange and process information,” Henson says.
Henson will create mathematical models that simulate how the neurons interact while Herzog will conduct and monitor the animal experiments and Kevrekidis will develop advanced simulation methods for solving the models.
“If you’ve ever traveled overseas,” Henson says, “You can certainly understand what we’re studying. Your body clock is thrown out of sync with the change in daylight hours you are used to, so jet lag sets in. Shift work can be viewed as chronic jet lag.”
Henson says that in case of jet lag, the body can adjust after a few days. In the case of shift workers or people who have constantly changing schedules, that adjustment is much harder to attain. He also says it’s not known how much of a shift in the light-dark cycle the body can experience before the negative effects take place. It’s also not known how much of that shift can be treated by drugs or light therapy, Henson says.