July 28, 2006
Volume 17, No. 15
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When our morning alarms startle us awake, their shrill tones rattling our nerves and propelling us out of bed, few of us ever stop to think about the complexity of our sleeping and waking cycles — or how far out of sync they often are with our natural rhythms. Timothy Monk, PhD, director of the Human Chronobiology Research Program at Western Psychiatric Institute and Clinic (WPIC), makes a living by doing exactly that.
Dr. Monk is one of the world’s leading experts on human circadian rhythms, the cyclical biologic processes that govern our behavior. “Circadian rhythms work,” says Dr. Monk, “to get us ready for sleep at night and wakefulness during the day.”
A special region of the brain referred to as the circadian pacemaker acts as an internal clock to control the rhythms, which range from body temperature and blood pressure to hormone production rates. Dr. Monk particularly is interested in what happens when this internal clock gets disrupted.
A study currently under way at WPIC, funded by the National Institute on Aging, is examining how aging disturbs the circadian clock. As we grow older, our natural rhythms gradually shift out of sync with our sleeping and waking cycles. This is why an elderly person may feel sleepy early in the evening but wide awake at bedtime. Researchers are attempting to enhance the subjects’ sleep quality by making slight alterations in their bedtimes. A similar study is designing ways to improve the sleep of bereaved seniors.
“As a group, older Americans consume huge quantities of sleeping pills,” Dr. Monk says, “and our hope is to improve their sleep using circadian principles so that pills can be avoided.”
Dr. Monk has worked extensively with NASA to study how space travel disrupts circadian rhythm. When astronauts go to space, their sleep schedules get rearranged and shifted out of alignment with their circadian clocks.
In time isolation labs at WPIC, researchers simulate the types of changes in routine that often are seen in space and observe their effects on the sleep quality, mood, and performance level of the subjects. Eventually, this research will help shed light on how our bodies are affected not only by space travel, but also by more common activities such as crossing time zones and working night shifts.