Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Timing of food consumption activates genes in specific brain area

01.08.2006
Giving up your regular late-night snack may be hard, and not just because it's a routine. The habit may genetically change an area of the brain to expect the food at that time, researchers at UT Southwestern Medical Center have discovered.

By training mice to eat at a time when they normally wouldn't, the researchers found that food turns on body-clock genes in a particular area of the brain. Even when the food stopped coming, the genes continued to activate at the expected mealtime.

"This might be an entrance to the whole mysterious arena of how metabolic conditions in an animal can synchronize themselves with a body clock," said Dr. Masashi Yanagisawa, professor of molecular genetics and senior author of the study.

The UT Southwestern researchers report their findings in the Aug. 8 issue of the Proceedings of the National Academy of Sciences.

The daily ups-and-downs of waking, eating and other bodily processes are known as circadian rhythms, which are regulated by many internal and external forces. One class of genes involved in these cycles is known as Period or Per genes.

When food is freely available, the strongest controlling force is light, which sets a body's sleep/wake cycle, among other functions. Light acts on an area in the brain called the suprachiasmatic nucleus, or SCN.

But because destroying the SCN doesn't affect the body clock that paces feeding behavior, the circadian pacemaker for feeding must be somewhere else, Dr. Yanagisawa said.

To find the answer, his group did a simple but labor-intensive experiment. The scientists set the mice on a regular feeding schedule, then examined their brain tissue to find where Per genes were turned on in sync with feeding times.

The researchers put the mice on a 12-hour light/dark cycle, and provided food for four hours in the middle of the light portion.

Because mice normally feed at night, this pattern is similar to humans eating at inappropriate times. Dysfunctional eating patterns play a role in human obesity, particularly in the nocturnal eating often seen in obese people, the researchers note.

The mice soon fell into a pattern of searching for food two hours before each feeding time. They also flipped their normal day/night behavior, ignoring the natural cue that day is their usual time to sleep.

After several days, the researchers found that the daily activation cycle of Per genes in the SCN was not affected by the abnormal feeding pattern.

However, in a few different areas of the brain, particularly a center called the dorsomedial hypothamalic nucleus or DMH, the Per genes turned on strongly in sync with feeding time after seven days.

When the mice subsequently went two days without food, the genes continued to turn on in sync with the expected feeding time.

"They started to show the same pattern of anticipatory behaviors several hours before the previously scheduled time of feeding," said Dr. Yanagisawa, a Howard Hughes Medical Institute investigator. "So somewhere in the body, they clearly remembered this time of day."

Upcoming research will focus on how the centers that control various body clocks communicate with each other, Dr. Yanagisawa said.

Aline McKenzie | EurekAlert!
Further information:
http://www.utsouthwestern.edu

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>