Featured Research

from universities, journals, and other organizations

Even in flies, enriched learning drives need for sleep, study finds

Date:
June 24, 2011
Source:
University of Wisconsin-Madison
Summary:
Just like human teenagers, fruit flies that spend a day buzzing around the "fly mall" with their companions need more sleep. That's because the environment makes their brain circuits grow dense new synapses and they need sleep to dial back the energy needs of their stimulated brains, according to a new study by sleep researchers.

New research shows that environment makes fruit fly brain circuits grow dense new synapses, in turn requiring the flies to sleep in order to dial back the energy needs of their stimulated brains.
Credit: Image courtesy of Dr. Chiara Cirelli, Wisconsin Center for Sleep and Consciousness

Just like human teenagers, fruit flies that spend a day buzzing around the "fly mall" with their companions need more sleep. That's because the environment makes their brain circuits grow dense new synapses and they need sleep to dial back the energy needs of their stimulated brains, according to a new study by UW-Madison sleep researchers.

Related Articles


Researchers saw this increase in the number of synapses -- the junctions between nerve cells where electrical or chemical signals pass to the next cell -- in three neuronal circuits they studied. The richer "wake experience" resulted in both larger synaptic growth and greater sleep need.

The study, published in the journal Science, provides structural evidence for the theory that "synaptic homeostasis" is one of the key reasons all animals need sleep. Researchers Dr. Daniel Bushey, Dr. Giulio Tononi and Dr. Chiara Cirelli of the Wisconsin Center for Sleep and Consciousness also looked at the role the gene implicated in Fragile X syndrome plays in re-normalizing the brain during sleep.

In one experiment, researchers took young fruit flies that spent the first days of their lives alone in single tubes too small to allow flying. Then they released them in groups into a large lighted chamber that allowed them to fly around together for their 12-hour day.

All the flies grew more synapses while they were awake for several hours, the research showed. But this was especially true for the flies in the enriched environment, which grew new branches with many new synapses. After their mall visit, the flies were put back into the single tubes and slept much longer for at least one day. Their synapses returned to normal size after sleep.

Those flies that visited the mall, but were deprived of sleep, continued to have synapses that were larger and denser.

"Sleep prunes back the new synapses; you have to create space for synapses to grow again or you can't learn again the next day," says Cirelli, associate professor of psychiatry at the School of Medicine and Public Health. "Even more importantly, the pruning saves energy, and for the brain, energy is everything. Learning without sleep is unsustainable from an energy point of view."

In earlier work, the lab also showed that the strengthened synapses had higher levels of proteins that build up during a day of learning, and that sleep also dials down protein levels.

In the current study, UW researchers also looked at the role of the gene Fmr1, which, when it isn't expressed in humans, results in Fragile X Syndrome, a cause of autism and mental disabilities. People with Fragile X also have difficulty sleeping.

In this study, the sleep researchers looked at what happens when Fmr1 is over-expressed; that is, when more Fmr1 protein is present in the brain. Previous work had shown that Fmr1 probably facilitates the pruning of synapses. Bushey and colleagues found that when Fmr1 is over-expressed, the increase in synapse number during wake does not occur, and the need for sleep declines.

"This suggests that if the synapses are already down regulated, there is less need for sleep," Cirelli says. "It is more evidence for the theory that sleep is driven by the need to reduce the brain's energy needs."

This research was funded by the National Institute of General Medical Sciences, the NIH Director's Pioneer Award and the Canadian Institutes of Health Research.


Story Source:

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


Journal Reference:

  1. Daniel Bushey, Giulio Tononi, Chiara Cirelli. Sleep and Synaptic Homeostasis: Structural Evidence in Drosophila. Science, 2011; 332 (6037): 1576-1581 DOI: 10.1126/science.1202839

Cite This Page:

University of Wisconsin-Madison. "Even in flies, enriched learning drives need for sleep, study finds." ScienceDaily. ScienceDaily, 24 June 2011. <www.sciencedaily.com/releases/2011/06/110623141316.htm>.
University of Wisconsin-Madison. (2011, June 24). Even in flies, enriched learning drives need for sleep, study finds. ScienceDaily. Retrieved October 30, 2014 from www.sciencedaily.com/releases/2011/06/110623141316.htm
University of Wisconsin-Madison. "Even in flies, enriched learning drives need for sleep, study finds." ScienceDaily. www.sciencedaily.com/releases/2011/06/110623141316.htm (accessed October 30, 2014).

Share This



More Mind & Brain News

Thursday, October 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Studying Effects of Music on Dementia Patients

Studying Effects of Music on Dementia Patients

AP (Oct. 30, 2014) The University of Wisconsin-Milwaukee is studying the popular Music and Memory program to see if music, which helps improve the mood of Alzheimer's patients, can also reduce the use of prescription drugs for those suffering from dementia. (Oct. 30) Video provided by AP
Powered by NewsLook.com
Techy Tots Are Forefront of London's Baby Show

Techy Tots Are Forefront of London's Baby Show

AP (Oct. 28, 2014) Moms and Dads get a more hands-on approach to parenting with tech-centric products for raising their little ones. (Oct. 28) Video provided by AP
Powered by NewsLook.com
Cocoa Could Be As Good For Memory As It Is For A Sweet Tooth

Cocoa Could Be As Good For Memory As It Is For A Sweet Tooth

Newsy (Oct. 27, 2014) Researchers have come up with another reason why dark chocolate is good for your health. A substance in the treat can reportedly help with memory. Video provided by Newsy
Powered by NewsLook.com
Five-Year-Olds Learn Coding as Britain Eyes Digital Future

Five-Year-Olds Learn Coding as Britain Eyes Digital Future

AFP (Oct. 27, 2014) Coding has become compulsory for children as young as five in schools across the UK. Making it the first major world economy to overhaul its IT teaching and put programming at its core. Duration: 02:19 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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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