Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Memory's Master Switch

30.07.2010
TAU discovers the molecular power behind memory

Neuroscientists have long wondered how individual connections between brain cells remain diverse and "fit" enough for storing new memories. Reported in the prestigious science journal Neuron, a new study led by Dr. Inna Slutsky of the Sackler School of Medicine at Tel Aviv University describes what makes some memories stick.

The key is GABA (ã-Aminobutyric acid), a natural molecule that occurs in the brain, which could be the main factor in regulating how many new memories we can generate, the new study has found. The understanding of these mechanisms might lead to the development of new memory enhancers and new treatments for neurodegenerative diseases such as Alzheimer's.

Memories, Dr. Slutsky says, are stored in synaptic connections between neurons in our brain. In the past, other teams, including her own, have demonstrated that the strength of individual synapses is highly variable, even at the single neuron level. This variability ultimately determines if and how new memories are stored, and the key to this variability is GABA, a naturally-occurring chemical found in the brain.

Tight connections and lone rangers

Dr. Slutsky's graduate student Tal Laviv and postdoctoral fellow Inbal Riven, the lead authors in the study, applied advanced nanotechnology methods in optical imaging to track how proteins engineered by Prof. Paul Slesinger and his team at The Salk Institute interact with GABA at the single-synapse level.

In the hippocampus, one of the main areas of the brain involved in learning and memory, the strength of neuronal connections is known to be highly variable. Some neurons are tightly connected to others, while some appear to be "lone rangers."

The new paper, which examines individual synapses in the hippocampus, demonstrates that this process is regulated by GABA, the main inhibitory neurotransmitter in our brain. "We determined that variations in the local level of GABA in the vicinity of individual synapses are responsible for the differences or 'heterogeneity' of synaptic strength. And this heterogeneity may facilitate the formation of new memories," Dr. Slutsky explains.

Looking at the brain at rest

While looking at the brain in its basal state — when the activity was "at rest" before attempting to memorize a list of items or after a memory had been stored — Dr. Slutsky's team could actually "see" where synapses differ at different dendritic branches in the neuronal network. Those branches of neurons close to a cell body displayed a larger number of weak synapses, while the most distant branches were composed of a smaller number of strong synapses.

"Why the difference?" they asked. GABA was the answer. Higher concentrations of GABA near a synapse induced a stronger activation of its receptors, weakening basal synapse strength. As a result, GABA makes this synapse more liable to the formation of new memories, the researchers propose.

Dr. Slutsky, who previously discovered a basal-state regulator molecule, says that the research may also have implications for treating diseases of the mind. "We found that amyloid-beta, a well-known hallmark of Alzheimer's disease, regulates basal synapse strength in an opposite way to GABA," she notes, suggesting that an increase in the basal activity of synapses may initiate memory decline in Alzheimer's and other neurodegenerative disorders.

Experiments in the study were done using neuronal cultures and brain slices of rats subjected to molecular biology, optical imaging and electrophysiological techniques. The study also constituted a technical achievement, since it used advanced imaging techniques such as fluorescence resonance energy transfer (FRET) spectroscopy that looked at protein-to-protein interactions in the brain at the 10 nanometer scale. In the past, such fine resolution was impossible — brain scientists could only investigate interactions at the level of entire tissues, not between molecules at individual synapses.

George Hunka | EurekAlert!
Further information:
http://www.aftau.org

More articles from Studies and Analyses:

nachricht The importance of biodiversity in forests could increase due to climate change
17.11.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

nachricht Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

IceCube experiment finds Earth can block high-energy particles from nuclear reactions

24.11.2017 | Physics and Astronomy

A 'half-hearted' solution to one-sided heart failure

24.11.2017 | Health and Medicine

Heidelberg Researchers Study Unique Underwater Stalactites

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>