Featured Research

from universities, journals, and other organizations

Hibernating lemurs hint at the secrets of sleep

Date:
September 4, 2013
Source:
Duke University
Summary:
By studying hibernation, scientists are providing a window into why humans sleep. Observations of a little-known primate called the fat-tailed dwarf lemur in captivity and the wild has revealed that it goes for days without the deepest part of sleep during its winter hibernation season. The findings support the idea that sleep plays a role in regulating body temperature and metabolism.

During hibernation, non-REM sleep is absent in the lemuriform primate Cheirogaleus medius.
Credit: Mackenzie Wing; Creative Commons Attribution License

By studying hibernation, a Duke University team is providing a window into why humans sleep. Observations of a little-known primate called the fat-tailed dwarf lemur in captivity and the wild has revealed that it goes for days without the deepest part of sleep during its winter hibernation season. The findings support the idea that sleep plays a role in regulating body temperature and metabolism.

Despite decades of research, why we sleep is still a mystery. Theories range from conserving energy, to processing information and memories, to removing toxins that build up when we're awake.

"If we spend nearly a third of our lives doing it, it must have some specific purpose," said lead author Andrew Krystal, a sleep researcher at Duke.

One theory is that sleep helps regulate body temperature and metabolism. In a study appearing Sept. 4 in the journal PLOS ONE, researchers have found support for the idea in the fat-tailed dwarf lemur (Cheirogaleus medius), a squirrel-sized primate native to the African island of Madagascar.

The closest genetic relatives to humans that are known to hibernate, fat-tailed dwarf lemurs spend up to seven months each year in a physiological state known as torpor, where the regulation of body temperature stops and metabolism slows down.

In torpor, these lemurs can drop their heart rate from 120 beats per minute to a mere 6, and breathing slows to a crawl. Instead of maintaining a steady body temperature like most mammals, their bodies heat up and cool down with the temperature of the outside air, fluctuating by as much as 25 degrees in a single day.

For most mammals, a change in body temperature by more than a few degrees for any period of time would be life-threatening. But for the fat-tailed dwarf lemur, hibernation is a way to conserve energy during Madagascar's long winter dry season, a time of year when food and water are in short supply.

If thermoregulation is one function of sleep, the researchers asked, can dwarf lemurs in torpor get away with less sleep?

To find out, they attached electrodes to the animals' scalps and returned them to their nests for monitoring. They studied dwarf lemurs hibernating in the wild on the west coast of Madagascar, and also non-torpid animals sleeping in captivity at the Duke Lemur Center. The researchers also measured oxygen intake and other vital signs.

They found that dwarf lemurs in torpor went for days without the slow-wave, low-amplitude brain activity associated with deep sleep.

Hibernating lemurs did show periods of brain activity consistent with the phase of sleep known as rapid eye movement (REM) sleep -- when most dreaming is believed to occur -- but only when winter temperatures rose above 25 degrees Celsius.

As a next step, the team is returning to the highlands of Madagascar to study another group of hibernators -- a family of small hedgehog-like animals called tenrecs.

By identifying similarities between dwarf lemurs and other hibernating animals, researchers may one day be able to induce hibernation-like states in humans.

Being able to push humans into standby mode by temporarily reducing heart rate and brain activity could buy time for patients who have suffered head trauma or heart attacks, extend the shelf life of transplant organs, or even open the door to long-distance space travel.


Story Source:

The above story is based on materials provided by Duke University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Andrew D. Krystal, Bobby Schopler, Susanne Kobbe, Cathy Williams, Hajanirina Rakatondrainibe, Anne D. Yoder, Peter Klopfer. The Relationship of Sleep with Temperature and Metabolic Rate in a Hibernating Primate. PLoS ONE, 2013; 8 (9): e69914 DOI: 10.1371/journal.pone.0069914

Cite This Page:

Duke University. "Hibernating lemurs hint at the secrets of sleep." ScienceDaily. ScienceDaily, 4 September 2013. <www.sciencedaily.com/releases/2013/09/130904204125.htm>.
Duke University. (2013, September 4). Hibernating lemurs hint at the secrets of sleep. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2013/09/130904204125.htm
Duke University. "Hibernating lemurs hint at the secrets of sleep." ScienceDaily. www.sciencedaily.com/releases/2013/09/130904204125.htm (accessed July 25, 2014).

Share This




More Plants & Animals News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Boy Attacked by Shark in Florida

Boy Attacked by Shark in Florida

Reuters - US Online Video (July 24, 2014) An 8-year-old boy is bitten in the leg by a shark while vacationing at a Florida beach. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Newsy (July 24, 2014) A new study claims a set of prehistoric T-Rex footprints supports the theory that the giant predators hunted in packs instead of alone. Video provided by Newsy
Powered by NewsLook.com
Bill Gates: Health, Agriculture Key to Africa's Development

Bill Gates: Health, Agriculture Key to Africa's Development

AFP (July 24, 2014) Health and agriculture development are key if African countries are to overcome poverty and grow, US software billionaire Bill Gates said Thursday, as he received an honourary degree in Ethiopia. Duration: 00:36 Video provided by AFP
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:

More Coverage


Only Known Hibernating Primate Has Unique Sleep Patterns

Sep. 4, 2013 Fat-tailed dwarf lemurs are the only primates known to hibernate, and new research suggests their sleep patterns during hibernation are markedly different from those of ground squirrels, which also ... read more
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