About My Health Careers Internship MedBlogs Contact us
Medindia LOGIN REGISTER
Advertisement

Find Out Why Humans Sleep

by Bidita Debnath on September 5, 2013 at 11:38 PM
Font : A-A+

 Find Out Why Humans Sleep

A Duke University team is providing a window into why humans sleep, by studying hibernation.

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.

Advertisement

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.
Advertisement

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.

Source: Eurekalert
Advertisement

Advertisement
News A-Z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
News Category
What's New on Medindia
Printed Temperature Sensors help with Continuous Temperature Monitoring
Health Benefits of Giloy
Breast Cancer Awareness Month 2021 - It's time to RISE
View all

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
Snoring Sleep Disorder : Restless Legs Syndrome Sleep Disorder: Sleepwalking Periodic Limb Movement Disorder REM Behavior Disorder Sleep Disturbances In Women Sleep Insomnia Obstructive Sleep Apnea Sleep Disorders: A Prelude 

Recommended Reading
Female Lemurs Outlive Males
Researchers have found that for an endangered lemur known as the Milne-Edwards' sifaka, females are ...
For Conservation Efforts Endangered Lemurs' Complete Genomes are Sequenced and Analyzed
In an effort to help guide conservation efforts the complete genomes of three separate populations ....
Lemurs Lose Weight With 'Life-Extending' Dietary Supplement
In a study on lemurs, researchers found that resveratrol-known as dietary supplement for its ......
Hibernation-Inducing Signaling Mechanism Identified
Research has demonstrated that hibernation is an essential survival strategy for some animals and .....
Insomnia
Difficulty in initiating and maintaining sleep is known as insomnia. It is a symptom that occurs due...
Obstructive Sleep Apnea
Obstructive sleep apnea should be suspected in overweight middle aged adults who snore loudly and w...
Periodic Limb Movement Disorder
Periodic limb movement disorder (PLMD) is a sleep disorder which causes repetitive cramping or jerki...
REM Behavior Disorder
REM Behavior Disorder (RBD) is a sleep disorder in which the person acts out dramatic or violent dre...
Sleep
Sleep is a behavioral state of restricted physical activity. It is controlled by our internal biolo...
Sleep Disorder : Restless Legs Syndrome
Restless legs syndrome (RLS) causes - An urge to move, usually due to uncomfortable sensations that...
Sleep Disorder: Sleepwalking
Sleepwalking or “Somnambulism,” is a type of parasomnia and has medico-legal implications...
Sleep Disorders: A Prelude
Sleep disorders include difficulty falling/staying asleep, falling asleep at inappropriate times, ex...
Sleep Disturbances In Women
The physical, emotional and hormonal changes that occur in women during puberty, menstrual cycle, pr...
Snoring
Turbulent airflow causes tissues of the nose and throat to vibrate and the noise produced by these v...

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2021

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use