Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sleep deprivation within five hours of learning impairs memory consolidation in mice

09.07.2003


Scientists at the University of Pennsylvania have found new support for the age-old advice to "sleep on it." Mice allowed to sleep after being trained remembered what they had learned far better than those deprived of sleep for several hours afterward.



The researchers also determined that the five hours following learning are crucial for memory consolidation; mice deprived of sleep five to 10 hours after learning a task showed no memory impairment. The results are reported in the May/June issue of the journal Learning & Memory.

"Memory consolidation happens over a period of hours after training for a task, and certain cellular processes have to occur at precise times," said senior author Ted Abel, assistant professor of biology at Penn. "We set out to pinpoint the specific window of time and area of the brain that are sensitive to sleep deprivation after learning."


Abel and his colleagues found that sleep deprivation zero to five hours after learning appeared to impair spatial orientation and recognition of physical surroundings, known as contextual memory. Recollection of specific facts or events, known as cued memory, was not affected. Because the brain’s hippocampus is key to contextual memory but not cued memory, the findings provide new evidence that sleep helps regulate neuronal function in the hippocampus.

Abel’s group studied fear conditioning in mice. Animals received a mild electric shock in conjunction with one of two different types of stimuli. Some mice were placed in a distinctive setting before receiving a shock, generating fear of that particular location. Others heard a tone shortly before a shock was administered, causing them to fear the tone.

Abel assessed the permanence of this fear conditioning by observing how frequently the mice froze -- remaining completely motionless for a number of seconds -- when exposed 24 hours later to the cue associated with the shock. Even when deprived of sleep, mice exposed to the audible tone remained fearful the following day.

But mice that had learned to associate a general physical environment with administration of an electric shock were less likely to do so after sleep deprivation. Sleep-deprived mice spent just 4 percent of their time frozen when returned to this environment the following day, compared to 15 percent among mice whose sleep was not disrupted in the five hours immediately after shock administration.

"It has been suggested that sleep serves a variety of physiological functions, ranging from energy conservation to refreshing the immune system," Abel said. "Another important hypothesis is that sleep regulates neuronal function during memory consolidation. Our findings provide support for this theory, and, by implicating hippocampal-dependent tasks during a specific time window, we have taken an initial step in clarifying the neural effects of sleep deprivation."


###
Abel’s co-authors are Laurel A. Graves and Allan I. Pack of Penn’s School of Medicine and Penn undergraduate Elizabeth A. Heller.

Steve Bradt | EurekAlert!
Further information:
http://www.upenn.edu/

More articles from Life Sciences:

nachricht The birth of a new protein
20.10.2017 | University of Arizona

nachricht Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>