Researchers at the University of Manchester think that they may be on the verge of a breakthrough in treating things like jet lag and seasonal depression. In research done on mice, which they think will apply to humans as well, they found that color plays an important role in setting the body’s internal clock.

That clock govern’s everything from telling us when it’s time to sleep to telling us when it’s time to eat.

“I think this work opens up how we’re just starting to scratch the surface and look at the environmental adaptations of clocks,” Carrie Partch, a biochemist at the University of California, Santa Cruz, who was not involved in the new study told Science Magazine.

Scientists have known for some time that light, or dark, play an important role in the body’s circadian rhythms. Little was known, however, about the role of the color or brightness of that light.

“As a sort of common sense notion people have assumed that the clock somehow measures the amount of light in the outside world. Our idea was that it might be doing something more sophisticated than that,” said Tim Brown.

Brown is a neuroscientist with the University of Manchester and the author of a study published in PLOS Biology.

The suprachiasmatic nucleus (SCN) is a region common to all vertebrates. The region is, essentially, the core of the body’s internal clock. It maintains electrical and chemical rhythms and resets about every 24 hours.

Brown and his team created an “artificial sky” made by an array of LED lights behind a screen to diffuse the light. The sky was placed above caged mice to simulate day and night without changes in the color of the light. Because mice are nocturnal, their circadian rhythms increase their body temperature at night. The researchers report that when color changes were removed from the equation, the internal clocks of the mice got confused and their peak temperatures began arriving 30 minutes earlier than normal.

The researchers also measured neutrons in the SCN by showing mice different colors and intensities of light. One-fourth of the neutrons they measured showed a strong reaction to changes in color. The researchers report that the strongest response was to short wavelength blue light, similar to the light that appears shortly after sunset.

The team confirmed that the temperature change was due to a change in the SCN by examining slices of the appropriate brain region from the test mice. The bodies internal clock continues to operate, to the best of its ability, even when removed from the animal to which it belongs. Because of this, the researchers were able to look at the samples to see whether the clock was running fast or slow.

If, in fact, the same process goes on in the human SCN the research could have implications for a variety of human sleep disorders.

“What this opens up is the possibility for enhancing existing ways of treating jet lag or things like seasonal depression disorder,” said Brown.