Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The Fabric for Weaving Memory

24.10.2012
Neurobiologists at Vienna’s Research Institute of Molecular Pathology have identified a mechanism involved in the formation of long-term memory in fruit flies. They describe their findings in the current issue of the journal Neuron.

The details of memory formation are still largely unknown. It has, however, been established that the two kinds of memory – long term and short term – use different mechanisms. When short-term memory is formed, certain proteins in the nerve cells (neurons) of the brain are transiently modified.


Drosophila melanogaster
IMP/Solvin Zankl

To establish long-term memory, the cells have to synthesize new protein molecules. This has been shown in experiments with animals. When drugs were used to block protein synthesis, the treated animals were not able to form long-term memory.

The precise mechanism by which the newly synthesized proteins regulate memory formation is still poorly understood. They are thought to strengthen existing connections between neurons, as well as establish new connections. Both processes are required for long-term memory formation.
A nerve cell in the brain makes connections with tens of thousands of other nerve cells through so-called synapses. When memory is formed, only specific synapses, which are activated by a specific experience are modified. The mechanism of how the synthesis of new proteins can be restricted to these activated synapses has been unclear. Neurobiologists have postulated the existence of “synaptic tags”. One of the candidates is a family of proteins known to regulate local protein synthesis, the CPEB family of proteins. These proteins have been known for some time to perform important tasks during embryonic development, and recently have been identified in neuronal synapses.

In 2007, Krystyna Keleman, a neuroscientist at the Research Institute of Molecular Pathology (IMP) in Vienna, was able to show that fruit flies require CPEB proteins for long-term memory formation.
To study memory formation, the researchers at the IMP looked at the sexual behavior of flies. After copulation, female flies loose interest in the courtship advances of males. Male flies must learn – by trial and error – that only virgin females are receptive. The key to telling them apart is their smell.

Researchers at the IMP have built tiny “trainig camps” to test the memory of fruit flies. In these devices, male flies are exposed to mated females for a defined period of time. Depending on the length of the training session, the resulting memory lasts for several hours to several days.

To find out how these molecules might function in long-term memory, Sebastian Krüttner, a doctoral student with Krystyna Keleman at the IMP, devoted the past five years to this question. He identified two very similar CPEB proteins in flies, Orb2A and Orb2B, as the key molecules. While both isoforms are required for the formation of long-term memory, they function by distinct mechanisms in this process.

After conducting a large number of genetic, biochemical and behavioral experiments, the IMP scientists now propose the following model for long-term memory formation: a learning experience – as in the courtship conditioning procedure – leads to the activation of Orb2A in certain synapses only. In these synapses, Orb2A recruits Orb2B into complexes, which in turn alter protein synthesis locally only in these activated synapses, thereby forming stable memories.

This model, which is described in the current issue of the journal Neuron, is somewhat unconventional. The fact that two very similar molecules have such different functions was unexpected. Even more surprising is the role of Orb2A, which does not require its protein binding domain – a region previously thought to be essential for CPEB proteins.

The mechanism by which the two proteins interact in the formation of memory might turn out to be a basic principle for members of the CPEB family. Since these proteins are highly conserved among animals including humans, the implications could be far reaching.

The paper „Drosophila CPEB Orb2A mediates memory independent of ist RNA-binding domain“ by Sebastian Krüttner et al. was published in the journal Neuron on October 18, 2012.
About Krystyna Keleman
Krystyna Keleman was born in Warsaw (Poland) and received her professional training in the USA and Switzerland. She graduated as a developmental neurobiologist from the University of Zurich. In 1998, Krystyna Keleman moved to Vienna where she currently holds an independent group leader position at the Research Institute of Molecular Pathology.

About the IMP
The Research Institute of Molecular Pathology (IMP) in Vienna is a basic biomedical research institute largely sponsored by Boehringer Ingelheim. With over 200 scientists from 30 nations, the IMP is committed to scientific discovery of fundamental molecular and cellular mechanisms underlying complex biological phenomena. Research areas include cell and molecular biology, neurobiology, disease mechanisms and computational biology. The IMP is a founding member of the Campus Vienna Biocenter.

Contact
Dr. Heidemarie Hurtl
IMP Communications
Tel.: (+43 1) 79730 3625
hurtl@imp.ac.at

Scientific Contact
keleman@imp.ac.at

Dr. Heidemarie Hurtl | idw
Further information:
http://www.imp.ac.at/research/research-groups/keleman-group/

More articles from Life Sciences:

nachricht Research team creates new possibilities for medicine and materials sciences
22.01.2018 | Humboldt-Universität zu Berlin

nachricht Saarland University bioinformaticians compute gene sequences inherited from each parent
22.01.2018 | Universität des Saarlandes

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Thanks for the memory: NIST takes a deep look at memristors

22.01.2018 | Materials Sciences

Radioactivity from oil and gas wastewater persists in Pennsylvania stream sediments

22.01.2018 | Earth Sciences

Saarland University bioinformaticians compute gene sequences inherited from each parent

22.01.2018 | Life Sciences

VideoLinks Wissenschaft & Forschung
Overview of more VideoLinks >>>