Biological clock study turns to knees

WASHINGTON, Jan. 15 (UPI) _ Sleep researchers are shining a bright spotlight on the knee as a potential new star in the study of the human biological clock.

In research conducted at Cornell University, scientists successfully reset the internal daily timekeeper by about three hours with a single burst of bright light to the back of the knee.

Scott Campbell, the scientist who led the federally funded study, says this may one day lead to simpler, more effective therapies for sleep disorders using portable illuminated knee pads, socks and wrist bands.

Until now, researchers believed the only way to change the sleep/wake cycle was with bright lights directed at the patient's eyes.

But, says Campbell this finding suggests there ``could be biological clocks all over the human body.'' Research on animals, from lizards to flies, has found timer cells other than in the eyes.

In the series of experiments on 15 volunteers, Campbell and Patricia Murphy, both of Cornell, White Plains, New York, found they could reset the internal clock by up to three hours using a fiber-optic pad attached to a halogen light and held onto the backs of knees with a brace.

The research is reported in the journal Science.

The scientists are not sure how the light messages are getting to the brain, but speculate they may be carried through blood.

Campbell also says any blood vessel-rich area _ armpits, feet and wrists, for example _ could be as effective as knees.

Dr. Michael Terman, an authority on light and sleep from Columbia University, New York City, calls the study ``provocative'' because it ``demonstrates a new input route for environmental light to the internal clock.''

But he says the ``implications for treatment are far from clear'' and he says many more experiments are needed before scientists will know if knee therapy can help insomniacs, shift workers and jet lagged travelers.

(Written by Mara Bovsun in New York) _- Copyright 1997 by United Press International All rights reserved _-