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 A novel synthetic antibody enables conditional “protein knockdown” in vertebrates
20.08.2018 | Technische Universität Dresden

nachricht Climate Impact Research in Hannover: Small Plants against Large Waves
17.08.2018 | Leibniz Universität Hannover

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Quantum bugs, meet your new swatter

20.08.2018 | Information Technology

A novel synthetic antibody enables conditional “protein knockdown” in vertebrates

20.08.2018 | Life Sciences

Metamolds: Molding a mold

20.08.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>