Owls and larks, check the biological clock!
"Owls" and "larks" differ from each other in the speed of the biological clock, localized in the hypothalamus. The speed of this clock, as it turned out, is programmed at the genetic level.
The results of the work of Swiss scientists from the University of Zurich, working under the guidance of Professor Steven Brown, indicate that almost every cell in the body has its own biological clock, the synchronous operation of which is provided by the hypothalamus. The most interesting finding is the fact that skin cells can be used to identify a genetic predisposition to habits or preferences such as lying in bed for a long time in the morning, late gatherings or getting up with the first rays of the sun.
The authors isolated cells from skin samples of 28 volunteers (11 "larks" and 17 "owls") and embedded in them a gene encoding a fluorescent protein. The marker gene was embedded in such a way that it was activated together with the Bmall gene, the expression of which varies depending on the phase of the circadian (circadian) rhythm. Thus, the scientists obtained a luminous "biological clock in a test tube", the brightness of which changed with periods slightly longer or shorter than 24 hours.
It turned out that the shortest periods of glow are characteristic of the cells of early risers, and the longest – for late-rising midnighters. This phenomenon, obviously, is the basis of a long–known fact: the individual duration of the biological day in "owls" is slightly longer, and in "larks" – less than astronomical days, and in order to sum up the internal clock, the body uses "accurate time signals" - daily changes in illumination.
The authors believe that the results obtained will form the basis of clinical screening to identify patients in need of treatment with abnormal circadian rhythms.
Article by Steven A. Brown et al. Molecular insights into human daily behavior published in the on-line version of PNAS 28.01.2008
Portal "Eternal youth" www.vechnayamolodost.ru
30.01.2008