Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New principle guides memory dynamics

22.08.2003


Weizmann Institute finding may lead to new treatments for psychological trauma



Is it possible to intentionally forget specific memories, without affecting other memories? Many would undoubtedly be happy to learn that unpleasant memories might be erased. This ability could be especially significant when it comes to the kind of traumatic memories that are debilitating to those experiencing them. It may well be that in the future, we will be able to wipe out, or at least dim, certain types of memories with controlled accuracy. A new fundamental rule governing the workings of the brain, recently discovered by a team of scientists in the Weizmann Institute of Science, headed by Prof. Yadin Dudai of the Neurobiology Department, constitutes a step towards reaching this goal.

Every memory that we acquire undergoes a "ripening" process (called consolidation) immediately after it is formed. In this process, it becomes impervious to outside stimulation or drugs that would obliterate it. Until recently, the accepted dogma was that for each separate item of memory, consolidation occurs just once, after which the time window that allows for "memory erasing" closes (usually about an hour or two after the memory is acquired).


However, evidence has lately come to light that a memory is open to disruption for a short period following each time this memory is recalled. If this is true, it means that it would be possible to recall a memory and, immediately after the act of remembering, to activate a "memory eraser" and wipe it out, even though years may have passed since the original memory was formed.

Research into the subject took place in leading labs around the world, but the results were indecisive, as in some cases it was found possible to erase old memories upon recall, while in others no evidence for this was found.

Prof. Dudai’s group have now identified a new principle guiding the activity of the brain’s memory systems, which sheds light on how memories are recalled and stabilized, and which can explain the puzzling discrepancies in the findings.

This principle delineates the conditions in which the recalled memory becomes re-sensitized to the activity of the "memory erasers." In order to understand the rule, think of the bits of information stored in our memories, each with many associations, some of which conflict with others. For instance, a certain food can bring up memories of taste – delicious or disagreeable; a person can be remembered in pleasant or unpleasant contexts, and so on.

When we next taste the food or see the person, all of the associated memories are called up in the blink of an eye, but in the end, only one of those memories will dictate our reaction (e.g. become dominant.) This memory will decide whether we will eat the food or reject it, or whether we will smile at our acquaintance or ignore him.

Prof. Dudai’s team found that only that recalled memory that won the competition for dominance was re-exposed to the time window of sensitivity to memory erasers, and it is this memory that must be consolidated once again before being reinstalled in the long-term memory.

In other words, the winner, in the appropriate circumstances, may lose all. Put succinctly, one can say the stability of the recalled memory is inversely correlated with its dominance. This discovery is likely to assist in the future in developing new methods of wiping out unwanted memories, and thus of treating some kinds of psychological trauma.

Research that deals with the physical basis of the processes and mechanisms of memory, especially those that involve chemical or other intervention, relies on animal subjects. Prof. Dudai and his team carried out their research with rats and fish, which are especially suited for this type of research. The rats learned to remember flavors; the fish learned to remember flashes of light, and in both instances, the animals were trained to associate them with conflicting memories. That is, the tastes were sometimes good and sometimes bad, and the light sometimes signaled danger and sometimes didn’t.

In both species, it was possible to show that the dominant memory – that which won out over other associated memories and determined subsequent behavior – was the only one that could be erased by giving the appropriate drug within a few minutes of the memory’s recall. The fact that the closer we get to the "basic hardware" of memory, the more similarities exist between different animals, including humans, paves the way to the possibility that certain drugs found to be effective in eliminating memories in animals will also work on humans. Studies on humans, however, are yet to be conducted.

The results of the study were published today in the scientific journal Science. Other than Prof. Dudai, participating in the study were research students Mark Eisenberg, Tali Kobilo, and Diego Berman.

Prof. Yadin Dudai’s research is supported by: Abe and Kathryn Selsky Foundation; Nella and Leon Benoziyo Center for Neurosciences; Lester Crown Brain Research Fund; Abramson Family Brain Research Program; Carl and Michaela Einhorn-Dominic Brain Research Institute; and Murray H. & Meyer Grodetsky Center for Research of Higher Brain Functions.

Prof. Dudai holds the Sara and Michael Sela Professorial Chair of Neurobiology.


###
The Weizmann Institute of Science, in Rehovot, Israel, is one of the world’s foremost centers of scientific research and graduate study. Its 2,500 scientists, students, technicians, and engineers pursue basic research in the quest for knowledge and the enhancement of humanity. New ways of fighting disease and hunger, protecting the environment, and harnessing alternative sources of energy are high priorities at Weizmann.

Alex Smith | EurekAlert!
Further information:
http://www.weizmann.ac.il/

More articles from Health and Medicine:

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>