Featured Research

from universities, journals, and other organizations

Food-related Clock In The Brain Identified

Date:
May 23, 2008
Source:
Beth Israel Deaconess Medical Center
Summary:
In investigating the intricacies of the body's biological rhythms, scientists have discovered the existence of a "food-related clock" which can supersede the "light-based" master clock that serves as the body's primary timekeeper.The findings, which appear in Science, help explain how animals adapt their circadian rhythms in order to avoid starvation, and suggest that by adjusting eating schedules, humans too can better cope with changes in time zones and nighttime schedules that leave them feeling groggy and jet-lagged.

In investigating the intricacies of the body's biological rhythms, scientists at Beth Israel Deaconess Medical Center (BIDMC) have discovered the existence of a "food-related clock" which can supersede the "light-based" master clock that serves as the body's primary timekeeper.

The findings, which appear in the May 23 issue of the journal Science, help explain how animals adapt their circadian rhythms in order to avoid starvation, and suggest that by adjusting eating schedules, humans too can better cope with changes in time zones and nighttime schedules that leave them feeling groggy and jet-lagged.

"For a small mammal, finding food on a daily basis is a critical mission," explains the study's senior author Clifford Saper, MD, PhD, Chairman of the Department of Neurology at BIDMC and James Jackson Putnam Professor of Neurology at Harvard Medical School. "Even a few days of starvation is a common threat in natural environments and may result in the animal's death."

The suprachiasmatic nucleus (SCN), a group of cells in the brain's hypothalamus, serves as the body's primary biological clock. The SCN receives signals about the light-dark cycle through the visual system, and passes that information along to another cell group in the hypothalamus known as the dorsomedial nucleus (DMH). The DMH then organizes sleep-wake cycles, as well as cycles of activity, feeding and hormones.

"When food is readily available," explains Saper, "this system works extremely well. Light signals from the retina help establish the animals' circadian rhythms to the standard day-night cycle." But, if food is not available during the normal wake period, animals need to be able to adapt to food that is available when they are ordinarily asleep.

In order to survive, animals appear to have developed a secondary "food-related" master clock. "This new timepiece enables animals to switch their sleep and wake schedules in order to maximize their opportunity of finding food," notes Saper, who together with lead author Patrick Fuller, PhD, HMS Instructor in Neurology and coauthor Jun Lu, MD, PhD, HMS Assistant Professor of Neurology, set out to determine exactly where this clock was located.

"In addition to the oscillator cells in the SCN, there are other oscillator cells in the brain as well as in peripheral tissues like the stomach and liver that contribute to the development of animals' food-based circadian rhythms," says Saper. "Dissecting this large intertwined system posed a challenge."

To overcome this obstacle, the authors used a genetically arrhythmic mouse in which one of the key genes for the biological clock, BMAL1, was disabled. They next placed the gene for BMAL1 into a viral vector which enabled them to restore a functional biological clock to only one spot in the brain at a time. Through this step-by-step analysis, the authors uncovered the feeding entrained clock in the DMH.

"We discovered that a single cycle of starvation followed by refeeding turns on the clock, so that it effectively overrides the suprachiasmatic nucleus and hijacks all of the circadian rhythms onto a new time zone that corresponds with food availability," says Saper. And, he adds, the implications for travelers and shift workers are promising.

"Modern day humans may be able to use these findings in an adaptive way. If, for example, you are traveling from the U.S. to Japan, you are forced to adjust to an 11-hour time difference," he notes. "Because the body's biological clock can only shift a small amount each day, it takes the average person about a week to adjust to the new time zone. And, by then, it's often time to turn around and come home."

But, he adds, by adapting eating schedules, a traveler might be able to engage his second "feeding" clock and adjust more quickly to the new time zone.

"A period of fasting with no food at all for about 16 hours is enough to engage this new clock," says Saper. "So, in this case, simply avoiding any food on the plane, and then eating as soon as you land, should help you to adjust -- and avoid some of the uncomfortable feelings of jet lag."

This research was supported by grants from the U.S. Public Health Service.


Story Source:

The above story is based on materials provided by Beth Israel Deaconess Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

Beth Israel Deaconess Medical Center. "Food-related Clock In The Brain Identified." ScienceDaily. ScienceDaily, 23 May 2008. <www.sciencedaily.com/releases/2008/05/080522145213.htm>.
Beth Israel Deaconess Medical Center. (2008, May 23). Food-related Clock In The Brain Identified. ScienceDaily. Retrieved April 24, 2014 from www.sciencedaily.com/releases/2008/05/080522145213.htm
Beth Israel Deaconess Medical Center. "Food-related Clock In The Brain Identified." ScienceDaily. www.sciencedaily.com/releases/2008/05/080522145213.htm (accessed April 24, 2014).

Share This



More Health & Medicine News

Thursday, April 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Pharma Braces for M&A Wave

Big Pharma Braces for M&A Wave

Reuters - Business Video Online (Apr. 22, 2014) Big pharma on the move as Novartis boss, Joe Jimenez, tells Reuters about plans to transform his company via an asset exchange with GSK, and Astra Zeneca shares surge on speculation that Pfizer is looking for a takeover. Joanna Partridge reports. Video provided by Reuters
Powered by NewsLook.com
Study Says Most Crime Not Linked To Mental Illness

Study Says Most Crime Not Linked To Mental Illness

Newsy (Apr. 22, 2014) A new study finds most crimes committed by people with mental illness are not caused by symptoms of their illness or disorder. Video provided by Newsy
Powered by NewsLook.com
Hagel Gets Preview of New High-Tech Projects

Hagel Gets Preview of New High-Tech Projects

AP (Apr. 22, 2014) Defense Secretary Chuck Hagel is given hands-on demonstrations Tuesday of some of the newest research from DARPA _ the military's Defense Advanced Research Projects Agency program. (April 22) Video provided by AP
Powered by NewsLook.com
How Smaller Plates And Cutlery Could Make You Feel Fuller

How Smaller Plates And Cutlery Could Make You Feel Fuller

Newsy (Apr. 22, 2014) NBC's "Today" conducted an experiment to see if changing the size of plates and utensils affects the amount individuals eat. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins