Internal Body Temperature Turns Back Circadian Clocks

Every 24 hours, millions of 'clocks' inside of our cells reset, helping to tune sleep patterns, blood pressure and metabolism. These clocks—which are actually sets of genes that turn on and off in a cyclical rhythm—are precisely synchronized thanks to tiny fluctuations in body temperature, according to a new study.Scientists knew that internal clocks in plants, bacteria, and cold-blooded animals such as lizards and fish are extremely sensitive to temperature. But this is the first study to show that the body's thermostat also controls mammalian body clocks, suggesting that temperature resets are "evolutionarily ancient," the researchers say."If you look very broadly across all living systems, it appears that the ability to use temperature to synchronize clocks is ubiquitous," notes Howard Hughes Medical Investigator Joseph S. Takahashi, who led the new work, which was published October 15, 2010 in Science. "Light and temperature seem to be the major universal cues."Read more at...HHMI News, October 2010.