SciTech

2017 Nobel Prize in Physiology awarded to scientists studying relation between circadian rhythms and light

Credit: Rebecca Enright/ Credit: Rebecca Enright/

The 2017 Nobel Prize in Physiology or Medicine was awarded to Jeffrey C. Hall of the University of Maine, Michael Rosbash of Brandeis University, and Michael W. Young of Rockefeller University for their studies of the biological clock. According to The Royal Swedish Academy of Sciences, the three scientists “were able to peek inside our biological clock and elucidate its inner workings. Their discoveries explain how plants, animals, and humans adapt their biological rhythm so that it is synchronized with the Earth's revolutions.”

Hall and Rosbash collaborated to identify and isolate the “period gene” in fruit flies at Brandeis University in the 1980s. This gene is responsible for encoding the protein that builds up at night when we sleep and degrades during the day. As such, the body takes many of its temporal cues based upon the different levels of this protein at different times of the day.

Young, however, discovered and isolated the “timeless gene,” responsible for producing the proteins required to stop the production of the proteins from the period gene. This cyclical production of these proteins is dependent upon the light in our environment. This principle is evident in the biology of our brains. An area of the brain, known as the suprachiasmatic nucleus (SCN) connects the retinas to the pineal gland, responsible for producing melatonin, which is directly responsible for regulating sleep.

From our sleep cycle to regulating our hormones, temperature, and metabolism, this microscopic biological “clock”, present in all carbon-based life forms — plants, animals, and humans controls our circadian rhythms and directly influences all aspects of our biology and is dependent upon the different levels of the aforementioned proteins within our cells. Their work led to the establishment of the field of chronobiology. The research into our circadian rhythms has yielded enormous dividends for people from all walks of life. Scientists are now studying how our circadian rhythms affect things such as hunger, cognitive function, stress, heart function and our immune systems.

Of more importance, however, is what happens is when these internal clocks are out of “sync” or not regular. For example, a study to determine the effects of social jet lag (shifting one’s sleep cycle by a few hours) found that shifting participants' sleep cycle by a mere one hour each day put the same kind of stress on the human body similar to that of being diabetic in a three-week trial.

Even though modern society is no longer slave to the rotations of our planet around the sun, the light-dark cycle still rules supreme. Light is still amongst the most impactful of influences on our general health through the circadian rhythm. This is because certain chemicals in our brain are only produced under the right lighting conditions and spending one’s day in a dimly lit environment or looking at bright lights right before we go to sleep can dampen our natural rhythms.

It is evident that our internal clocks are an imperative facet of our lives.