Featured Research

from universities, journals, and other organizations

Temperature rhythms keep body clocks in sync

Date:
October 15, 2010
Source:
UT Southwestern Medical Center
Summary:
Researchers have found that fluctuations in internal body temperature regulate the body's circadian rhythm, the 24-hour cycle that controls metabolism, sleep and other bodily functions.

The suprachiasmatic nucleus responds to light entering the eye, and so is sensitive to cycles of day and night.
Credit: iStockphoto/Inga Ivanova

Researchers at UT Southwestern Medical Center have found that fluctuations in internal body temperature regulate the body's circadian rhythm, the 24-hour cycle that controls metabolism, sleep and other bodily functions.

A light-sensitive portion of the brain called the suprachiasmatic nucleus (SCN) remains the body's "master clock" that coordinates the daily cycle, but it does so indirectly, according to a study published by UT Southwestern researchers in the Oct. 15 issue of Science.

The SCN responds to light entering the eye, and so is sensitive to cycles of day and night. While light may be the trigger, the UT Southwestern researchers determined that the SCN transforms that information into neural signals that set the body's temperature. These cyclic fluctuations in temperature then set the timing of cells, and ultimately tissues and organs, to be active or inactive, the study showed.

Scientists have long known that body temperature fluctuates in warm-blooded animals throughout the day on a 24-hour, or circadian, rhythm, but the new study shows that temperature actually controls body cycles, said Dr. Joseph Takahashi, chairman of neuroscience at UT Southwestern and senior author of the study.

"Small changes in body temperature can send a powerful signal to the clocks in our bodies," said Dr. Takahashi, an investigator with the Howard Hughes Medical Institute. "It takes only a small change in internal body temperature to synchronize cellular 'clocks' throughout the body."

Daily changes in temperature span only a few degrees and stay within normal healthy ranges. This mechanism has nothing to do with fever or environmental temperature, Dr. Takahashi said.

This system might be a modification of an ancient circadian control system that first developed in other organisms, including cold-blooded animals, whose daily biological cycles are affected by external temperature changes, Dr. Takahashi said.

"Circadian rhythms in plants, simple organisms and cold-blooded animals are very sensitive to temperature, so it makes sense that over the course of evolution, this primordial mechanism could have been modified in warm-blooded animals," he said.

In the current study, the researchers focused on cultured mouse cells and tissues, and found that genes related to circadian functions were controlled by temperature fluctuations.

SCN cells were not temperature-sensitive, however. This finding makes sense, Dr. Takahashi said, because if the SCN, as the master control mechanism, responded to temperature cues, a disruptive feedback loop could result, he said.

Dr. Seung-Hee Yoo, instructor of neuroscience, and former graduate student Ethan Buhr also participated in the investigation.

The study was funded by the National Institutes of Health and the HHMI.


Story Source:

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


Journal Reference:

  1. E. D. Buhr, S.-H. Yoo, J. S. Takahashi. Temperature as a Universal Resetting Cue for Mammalian Circadian Oscillators. Science, 2010; 330 (6002): 379 DOI: 10.1126/science.1195262

Cite This Page:

UT Southwestern Medical Center. "Temperature rhythms keep body clocks in sync." ScienceDaily. ScienceDaily, 15 October 2010. <www.sciencedaily.com/releases/2010/10/101014144314.htm>.
UT Southwestern Medical Center. (2010, October 15). Temperature rhythms keep body clocks in sync. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2010/10/101014144314.htm
UT Southwestern Medical Center. "Temperature rhythms keep body clocks in sync." ScienceDaily. www.sciencedaily.com/releases/2010/10/101014144314.htm (accessed April 23, 2014).

Share This



More Health & Medicine News

Wednesday, April 23, 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