Now researchers, including a University of Washington biologist, have found hints that differing molecular processes in an area of the brain known as the suprachiasmatic nucleus might play a significant role in those jet lag differences.
Human circadian clocks operate on a period about 20 minutes longer than one day and so must be synchronized to the light-dark cycle of the solar day, delaying or advancing their time in response to light.
Someone whose clock runs faster than a solar day must delay it on a daily basis, and someone whose clock runs slower than a solar day must advance it. These daily adjustments happen naturally, and without our noticing, but the process is disrupted by sudden large shifts in the light-dark cycle because of a radically new geographic location.
Researchers previously learned that delaying the circadian clock happens through different pathways in the suprachiasmatic nucleus than advancing the clock does. The new research shows that, at a molecular level, the mechanisms responsible for resetting the expression of the “clock genes” are drastically different.
“We have known for decades that, in humans and other organisms, advances are always much harder to achieve than delays. For example, compare jet lag going to Europe with that coming back,” said Horacio de la Iglesia, a UW associate professor of biology.
“One of the reasons may be that these two forms of resetting the clock involve different molecular mechanisms at the clock level,” he said.
de la Iglesia and William Schwartz of the University of Massachusetts Medical School are corresponding authors of a paper detailing the research, published online recently (Oct. 3) in the Proceedings of the National Academy of Sciences. Co-authors are Mahboubeh Tavakoli-Nezhad, Christopher Lambert and David Weaver, also of the University of Massachusetts Medical School.
The researchers exposed hamsters to two light-dark cycles, one of 23.33 hours and the other at 24.67 hours, to test the mechanisms that advance and delay the circadian clock. A one-hour light pulse in the shorter cycle acted as dawn, but in the longer cycle it acted as dusk. The scientists confirmed that the pulse of light at dawn advanced the animals’ circadian clocks, while the light at dusk delayed the clocks.
The results suggest that different molecular mechanisms in the suprachiasmatic nucleus are at work when the circadian clocks are advanced than when the clocks are delayed, de la Iglesia said.
That could provide clues for understanding how circadian clocks work in nocturnal animals in natural conditions, and it could help in understanding potential remedies for jet lag.
The work was supported by a grant from the National Institutes of Health.
For more information, contact de la Iglesia at 206-616-4697, 206-616-3932 or firstname.lastname@example.org, or Schwartz at 508-856-5666 or email@example.com.
An abstract of the paper is available at http://www.pnas.org/content/early/2011/09/29/1107848108.abstract
Vince Stricherz | Newswise Science News
Nesting aids make agricultural fields attractive for bees
20.07.2017 | Julius-Maximilians-Universität Würzburg
The Kitchen Sponge – Breeding Ground for Germs
20.07.2017 | Hochschule Furtwangen
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision
Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...
19.07.2017 | Event News
12.07.2017 | Event News
12.07.2017 | Event News
20.07.2017 | Information Technology
20.07.2017 | Materials Sciences
20.07.2017 | Physics and Astronomy