What controls the sleep-wake rhythm? Three American scientists receive the prestigious prize for their findings on the internal clock.

To sleep or not to sleep, that is the question Photo: dpa

Three U.S. geneticists Jeffrey C. Hall, Michael Rosbash and Michael W. Young will receive this year’s Nobel Prize in Medicine for their research on the internal clock of humans and other living creatures. The three scientists have discovered molecular mechanisms that control the sleep-wake rhythm, the Nobel committee said Monday in Stockholm. Hall, Rosbash and Young share prize money of nine million Swedish kronor (about 940,000 euros).

"Her discoveries explain how plants, animals and humans adapt their bio-rhythms so that they are synchronized with the revolutions of the Earth," the Nobel Prize Committee of Stockholm’s Karolinska Institute said in explaining its decision. Life on our planet is adapted to the Earth’s rotation and thus has a sleep-wake rhythm adapted to day and night.

Hall, Rosbash and Young have succeeded in gaining insight into this internal clock, which also influences hormone levels, blood pressure and body temperature, among other things, they added.

Hall and his colleague Rosbash at Brandeis University in Boston and their colleague Young at Rockefeller University in New York had studied fruit flies as an example of living creatures on Earth and isolated a gene in these flies in 1984 that determines the daily bio-rhythm.

Laureate is "shocked" by the news

Hall and Rosbash proved that this gene contains the blueprint for a protein that accumulates in the cell at night and is degraded during the day. Young identified a second gene in 1994 that significantly affects the internal clock of living things.

Rosbash said Monday in a phone call with the Swedish news agency TT that he was "shocked" by the news from Stockholm. "I’m sitting here in my pajamas with my wife, I didn’t think of anything like this," the 73-year-old said, describing his surprise. He said he wished his mother had lived to see the honor.

The award will be presented to Rosbash, 72-year-old Hall and 68-year-old Young on Dec. 10 in Stockholm. Last year, Japanese cell biologist Yoshinori Ohsumi was awarded the Nobel Prize in Medicine. He was honored for his achievements in researching the so-called autophagy (self-digestion) of cells.

It had been suspected that this year Heidelberg virologist Ralf Bartenschlager and U.S. researchers Charles Rice and Michael Sofia could receive the Nobel Prize in Medicine for their research on the treatment of the liver disease hepatitis C

Sweden’s public broadcaster SR had speculated that this year Heidelberg virologist Ralf Bartenschlager and U.S. researchers Charles Rice and Michael Sofia could receive the Nobel Prize in Medicine for their research on the treatment of the liver disease hepatitis C. The most recent winner was Thomas Sudhof in 2013. The last time a German was honored with the Nobel Prize in Medicine was in 2013 with Thomas Sudhof.

The announcement of the winners of the Nobel Prize in Medicine ushered in the Nobel season, as it does every year. It will be followed on Tuesday by the Nobel Prize for Physics and on Wednesday for Chemistry. The Nobel Prize for Literature will be announced on Thursday, as confirmed on Monday. On Friday, the most eagerly awaited winner of the Nobel Peace Prize will be announced in Oslo, and finally the winner of the Nobel Prize for Economics will be announced next Monday.

The award ceremony and subsequent banquet in honor of the honorees takes place every year on December 10 at Stockholm City Hall. The Nobel Peace Prize is presented in Oslo.