It’s finally that time of year again: when we celebrate human achievements with prize money from the guy who felt guilty about inventing dynamite! In the first in a series, we’ll be discussing the Nobel Prize in Physiology or Medicine (that’s the royal “we” — you aren’t doing jack shit, as usual).
This year’s prize goes to Jeffrey C. Hall, Michael Rosbash, and Michael W. Young for research identifying the mechanism for the circadian rhythm. As most of you know, the earth revolves around the sun, and spins on an axis, resulting in a 24-hour day/night cycle (frankly, the fact that I had to say “most of you” deeply upsets me; I cannot fucking believe we’re having this debate, flat-Earthers).
For most organisms, there’s good reason to act differently during the day than during the night: the ability (or inability) to see in the dark, temperature changes, and the activities of predators and prey. But our brains can do more than visually detect that it’s light or dark to tell the time of day: the body itself can tell if it’s morning, afternoon, evening, or time for sweet, sweet sleep. (This is why you get jet-lagged, even though you can see that IT’S DARK OUT, BRAIN! IT’S 3 AM, WHY ARE WE AWAKE?) This is our internal sense of time: our circadian rhythm.
In the ’80s and early ’90s, Hall, Rosbash, and Young demonstrated that mutations in a certain gene in Drosophila, the fruit fly, interferes with the organism’s circadian rhythm. Because of their work, we know that this gene, called period, produces a protein called “PER.” In the morning, PER starts to accumulate. This signals certain cell functions, like hormone production and cell metabolism, but it also inhibits its own synthesis. Basically, it acts its own “off” switch: as PER does its job, it also screams “SOMEBODY STOP ME!” When PER reaches a high enough concentration in the cell, it produces enough “off” proteins to shut down its own production, telling the cell that it’s night time.
Since the discovery of this gene in Drosophila, three similar genes in humans have been identified, and further research by Hall, Young, and Rosbash has elucidated how this cycle is fine-tuned and responds to light. Over the following decades this work has had a significant impact on how biologists and physicians consider health and metabolism. It has since been established that obesity and diabetes, for example, can be exacerbated by eating later, when the digestive system’s clock says it shouldn’t be eating. Similarly, doctors can determine the best time of day to take certain drugs for maximum effect. These issues are particularly important in an age when we routinely travel, work unusual hours, and are constantly bombarded by artificial light.
So in the future, please print out Dr. Science’s articles, and read only by sunlight (or candles, if you must).