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 Closing in on advanced prostate cancer
13.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)

nachricht Visualizing single molecules in whole cells with a new spin
13.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

A whole-body approach to understanding chemosensory cells

13.12.2017 | Health and Medicine

Water without windows: Capturing water vapor inside an electron microscope

13.12.2017 | Physics and Astronomy

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>