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 Lab-free infection test could eliminate guesswork for doctors
26.02.2020 | University of Southampton

nachricht MOF co-catalyst allows selectivity of branched aldehydes of up to 90%
26.02.2020 | National Centre of Competence in Research (NCCR) MARVEL

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: High-pressure scientists in Bayreuth discover promising material for information technology

Researchers at the University of Bayreuth have discovered an unusual material: When cooled down to two degrees Celsius, its crystal structure and electronic properties change abruptly and significantly. In this new state, the distances between iron atoms can be tailored with the help of light beams. This opens up intriguing possibilities for application in the field of information technology. The scientists have presented their discovery in the journal "Angewandte Chemie - International Edition". The new findings are the result of close cooperation with partnering facilities in Augsburg, Dresden, Hamburg, and Moscow.

The material is an unusual form of iron oxide with the formula Fe₅O₆. The researchers produced it at a pressure of 15 gigapascals in a high-pressure laboratory...

Im Focus: From China to the South Pole: Joining forces to solve the neutrino mass puzzle

Study by Mainz physicists indicates that the next generation of neutrino experiments may well find the answer to one of the most pressing issues in neutrino physics

Among the most exciting challenges in modern physics is the identification of the neutrino mass ordering. Physicists from the Cluster of Excellence PRISMA+ at...

Im Focus: Therapies without drugs

Fraunhofer researchers are investigating the potential of microimplants to stimulate nerve cells and treat chronic conditions like asthma, diabetes, or Parkinson’s disease. Find out what makes this form of treatment so appealing and which challenges the researchers still have to master.

A study by the Robert Koch Institute has found that one in four women will suffer from weak bladders at some point in their lives. Treatments of this condition...

Im Focus: A step towards controlling spin-dependent petahertz electronics by material defects

The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.

Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...

Im Focus: Freiburg researcher investigate the origins of surface texture

Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.

Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

70th Lindau Nobel Laureate Meeting: Around 70 Laureates set to meet with young scientists from approx. 100 countries

12.02.2020 | Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

 
Latest News

Scientists 'film' a quantum measurement

26.02.2020 | Physics and Astronomy

Melting properties determine the biological functions of the cuticular hydrocarbon layer of ants

26.02.2020 | Interdisciplinary Research

Lights, camera, action... the super-fast world of droplet dynamics

26.02.2020 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>