Circadian Clock Sets at Lunchtime (broadcast Friday, May 23rd, 2008)

It's been known for years that the brains of many organisms incorporate a 'circadian clock,' a biological timekeeping mechanism that connects the body's rhythms to external light levels. The clock helps the body sync with changing daylight conditions -- a trick that can be used in conjunction with exposure to bright lights to help readjust the body's internal clocks to combat jet lag. Writing this week in the journal Science, researchers report that mice seem to have a second, independent circadian clock that connects to food consumption -- and it can overrule the regular light-based clock.

The food-synced clock, the researchers believe, could be used in nature to help animals adjust to hard times. "This new timepiece enables animals to switch their sleep and wake schedules in order to maximize their opportunity of finding food," explained Clifford Saper, one of the authors of the report. We'll talk him about the find, and what significance it might have for people. Teachers, find more information about using Science Friday as a classroom resource in the Kids' Connection.

Guests

Clifford Saper
James Jackson Putnam Professor of Neurology and Neuroscience, Harvard Medical School
Chairman, Department of Neurology
Beth Israel Deaconess Medical Center
Boston, MA