June 23, 2024

I, Science

The science magazine of Imperial College

The 2017 Nobel Prize in Physiology or Medicine was awarded jointly to Jeffrey C. Hall, Michael Rosbash and Michael W. Young "for their discoveries of molecular mechanisms controlling the circadian rhythm".

The 2017 Nobel Prize for Physiology or Medicine

This article belongs to a series on the 2017 Nobel Prizes

Isn’t it strange that when I have a cold I feel so much worse first-thing in the morning? Jet-lag really is a pain, isn’t it? Why does darkness make me feel sleepy? All of these things we might fleetingly consider, but there are some scientists who are working to give us more detailed answers to these considerations – and they’ve clocked-in enough years to have been awarded the 2017 Nobel Prize for Physiology or Medicine.

Many of us like to think we are in control of our bodies, our actions and the decisions we make. This, to an extent, is true. However, there are certain aspects of our wellbeing that are heavily influenced by something else: when we eat and when we decide to sleep, for example. This isn’t divine intervention here, but a process known as a circadian rhythm which, essentially, is a molecular body clock. And it’s not just humans who possess this kind of rhythm — it extends to fungi, plants and animals too, and that’s where it all started.

Jeffrey Hall, Michael Rosbash and Michael Young are joint winners of this year’s prestigious award, and together, they unravelled a piece of information that will revolutionise human science forever. Period was the key gene Jeffrey and Michael managed to isolate in fruit flies in 1984. We’ve known for a long time that we as humans follow some kind of daily rhythm. We sleep and wake at regular intervals, as we do feed and fast, but the mechanism behind this, up until 1984, had been difficult to elucidate.

Together, Jeffery and Michael discovered a protein we call PER. Fruit flies were seen to possess higher levels of this protein at night, and lower levels during the day, and this pattern occurred across a 24-hour period. It’s fair to say this discovery in fruit flies left scientists buzzing. Scientists which included Michael Young, who in 1994 went on to identify further genes and proteins involved in the regulation of PER, further unravelling the intricate feedback loop — what we now call our circadian rhythm.

This discovery has had vast impact on research into human wellbeing. We now know that humans exhibit ‘clocks’ in almost every cell of the body, controlled by a grandfather, ‘master’ clock in an area of our brains known as the Suprachiasmatic Nucleus (SCN). This clock regulates our sleep-wake and feed-fast cycles, and the maintenance of our core body temperature, to name just a few examples. But where’s the real impact of this science, and how is it benefiting human health?

Just as you can change the hands of that watch sitting on your wrist, there are a number of ways in which we can override our inherent body clocks. Some of these things are simple: caffeine consumed three hours prior to sleep has been shown to change the normal functioning of the circadian clock, with exercise also influencing the rhythm due to the subsequent release of hormones. Actually, if you want a good night’s sleep, research has shown that early-evening exercise is beneficial as it raises the levels of a hormone known as melatonin, helping us feel sleepy.

Since the mechanistic discovery of the circadian rhythm, a lot of research has looked into shift-workers and how the disruption of their circadian rhythms may influence their health. In fact, those who have irregular sleep patterns have been shown to be more likely to develop certain types of cancer, as well as stomach ulcers and sleep disorders. Those who work in healthcare, for example, have no choice but to work night shifts, but this discovery now means we are in a position to explore ways in which we can alter our circadian rhythms to fit in with modern-day societal expectations.

It’s difficult to estimate the significance of this discovery, but the impact now stretches far beyond what scientists may have first thought. Our immune system, the system that fights off harmful bacteria and viruses, works more efficiently at certain times of the day. Could it be that the flu vaccine some choose to be inoculated with every winter should be preferably administered in the morning? Could it be that if I’m exposed to a virus at night, I’m less likely to get sick than if I am exposed to it during the day? All of these questions are now being meticulously explored by scientists across the globe, thanks to the initial discoveries in fruit flies made by Jeffrey Hall, Michael Rosbash and Michael Young. Worthy winners, whose timeless timely science has, and will continue to have, implications in more ways than we can imagine.

Rachel Kahn is studying for an MSc in Science Communication at Imperial College London

Banner Image: Matteo Ianeselli, Old alarm clocks on the street market in Trento, Italy