Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A trace of memory

23.10.2013
Researchers watch neurons in the brain during learning and memory recall

A team of neurobiologists led by Simon Rumpel at the Research Institute of Molecular Pathology (IMP) in Vienna succeeded in tracking single neurons in the brain of mice over extended periods of time.


Cross section of the auditory cortex of a mouse brain. A single neuron is highlighted by green fluorescent protein. Dendritic spines that are visible along the processes correspond to excitatory synapses.

Copyright: IMP

Advanced imaging techniques allowed them to establish the processes during memory formation and recall. The results of their observations are published this week in PNAS Early Edition.

Most of our behavior – and thus our personality – is shaped by previous experience. To store the memory of these experiences and to be able to retrieve the information at will is therefore considered one of the most basic and important functions of the brain. The current model in neuroscience poses that memory is stored as long-lasting anatomical changes in synapses, the specialized structures by which nerve cells connect and signal to each other.

At the Research Institute of Molecular Pathology (IMP) in Vienna, Simon Rumpel and Kaja Moczulska used mice to study the effects of learning and memorizing on the architecture of synapses. They employed an advanced microscopic technique called in vivo two-photon imaging that allows the analysis of structures as small as a thousandth of a millimetre in the living brain.

Using this technology, the neurobiologists tracked individual neurons over the course of several weeks and analysed them repeatedly. They focussed their attention on dendritic spines that decorate the neuronal processes and correspond to excitatory synapses. The analyses were combined with behavioral experiments in which the animals underwent classic auditory conditioning.

The results showed that the learning experience triggered the formation of new synaptic connections in the auditory cortex. Several of these new structures persisted over time, suggesting a long-lasting trace of memory and confirming an important prediction of the current model.

Apart from the changes during memory formation, the IMP-scientists were interested in the act of remembering. Earlier studies had shown that memory recall is associated with molecular processes similar to the initial formation of memory. These similarities have been suggested to reflect remodelling of memory traces during recall.

To test this hypothesis, previously trained mice were exposed to the auditory cue a week after conditioning while tracking dendritic spines in the auditory cortex. The results showed that although some molecular processes indeed resembled those during memory formation, the anatomical structure of the synapses did not change. These findings suggest that memory retrieval does not lead to a modification of the memory trace per se. Instead, the molecular processes triggered by memory formation and recall could reflect the stabilization of previously altered or recently retrieved synaptic connections.

The primary goal of elucidating the processes during memory formation and recall is to increase our basic knowledge. Insights gained from these studies might however help us to understand diseases of the nervous system that affect memory. They may also, in the future, provide the basis for treatments that offer relief to traumatized patients.

Original publication
Kaja Ewa Moczulska, Juliane Tinter-Thiede, Manuel Peter, Lyubov Ushakova, Tanja Wernle, Brice Bathellier and Simon Rumpel: Dynamics of dendritic spines in the mouse auditory cortex during memory formation and memory recall. In: PNAS, online Early Edition, 22 October, 2013.
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.
Contact
Dr. Heidemarie Hurtl
IMP Communications
Dr. Bohr Gasse 7
1030 Vienna, Austria
Tel.: (+43 1) 79730 3625
Mobile: (+43 1) 664 8247910
hurtl@imp.ac.at

Dr. Heidemarie Hurtl | idw
Further information:
http://www.imp.ac.at

More articles from Life Sciences:

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

nachricht Pollen taxi for bacteria
18.07.2018 | Technische Universität München

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>