Body Clocks Dictate The Beat Of Life

Main Category: Endocrinology
Also Included In: Biology / Biochemistry;  Genetics
Article Date: 14 Jun 2008 - 6:00 PDT

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Body clocks determine whether people are early birds or late risers, "homebodies" or "party animals". As Professor Hanspeter Herzel (Institute for Theoretical Biology, Humboldt University Berlin, Germany) now reported at the international conference "Computational & Experimental Molecular Biology" in Berlin, Germany, these biological watches not only regulate the sleep-wake cycle, but also blood pressure and blood temperature. "They are controlled by a master clock which consists of 20,000 neurons in the brain," Professor Herzel illuminated, "where they operate together to adapt us to the changing demands of day and night."

Humans and animals have a master clock which prescribes the general time after which all other body cells set their watches. The human master clock consists of around 20,000 neurons located in the brain directly above the optic nerve. The master clock is connected by delicate nerve fibres to the optic nerve which re-sets the master clock every day.

But how does the master clock coordinate its 20,000 different neurons so that they all beat at the right time and pass on the correct rhythm? The neurons communicate amongst themselves via second messengers, called neuro transmitters and, thus, they inform their neighbours about the time. When all neurons of the master clock have agreed on a rhythm, they activate the internal clocks of all other body cells and influence the behaviour but also the metabolism of humans.

Germany: Around 15 per cent do not live in sync with their Body Clock
"Not only the sun sets our body clock," Prof. Herzel explained at the MDC conference. "Clock genes determine a good portion of the body's rhythm." For example, the clock genes decide whether people tend to be either early worms or late raisers.

"Around 15 per cent of the Germans do not live in sync with their body clock," said Prof. Herzel. Against their nature, they try to adapt themselves to the timeframes of work and friends. Hence, they often suffer from insomnia and headaches. Frequent travelling over several time zones can also lead to disturbances. Using a new examination method, physicians can now determine whether these troubles are caused by genetic variations in the clock genes. Meanwhile, individual adapted light therapies are possible.

Participants in the 3-day conference, which ends on Saturday, includes more than 100 scientists and young researchers from the USA, Israel, and Europe. The main discussions of the meeting focus on the new branch of research "Systems Biology" which combines computational and experimental molecular biology. Rather than examining single genes or proteins, systems biologists study how such genes and gene products are controlled and how they interact together. The conference organizers are Professor Nikolaus Rajewsky (MDC), Professor Hermann-Georg Holzhütter (Charité, Berlin, Germany), and Professor Dimitris Thanos (Biomedical Research Foundation, Academy of Athens, Greece).

Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch
Robert-Rössle-Straße 10; 13125 Berlin; Germany

Further Information: http://itb.biologie.hu-berlin.de/Research/faculty/herzel_group

http://www.mdc-berlin.de