Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Molecular learning machines under the microscope

18.08.2014

Neurotransmitters play an important role in the communication of nerve cells. Major details of the processes involved have been unclear until recently. Scientists of the University of Würzburg have now shed light on these processes by using a new technique.

All human thoughts, feelings and actions are based on the fact that nerve cells communicate with each other. They pass impulses via synapses, intensify, weaken or block them. Like a ferry crossing a river, chemical messengers, the so-called neurotransmitters, pass from one side of the synapse to the other crossing a gap that is less than thousands of millimetres wide to dock to special synaptic receptors on the adjacent neuron.


Organisation of the Bruchpilot protein at active zones. High-resolution dSTORM imaging (right) shows details that cannot be visualised using conventional optical microscopy (left). Scale bars 500 nm. Photo: team Sauer / team Kittel

The molecular make-up of synaptic structures responsible for passing impulses is not fully known until today. Using a special imaging technique, scientists from the University of Würzburg have now succeeded in making processes at the nanoscale visible. They present their results in the latest issue of Nature Communications.

Molecular machines in active zones

"The release of neurotransmitters in the so-called 'active zone' - a highly specialised sub-cellular region of the presynaptic neuron - is responsible for the information transfer at chemical synapses," explains Dr. Robert Kittel, who is the head of an Emmy Noether Group at the Department of Physiology of the University of Würzburg which focuses on the molecular mechanisms of synapses.

Since 2009, he has studied the fruit fly Drosophila melanogaster to learn more about the active zone's physiology. He is particularly interested in the question of how structural changes of this active zone contribute to synaptic plasticity, thus enabling learning, for instance.

As Kittel puts it, "complex molecular machines" are at work in an active zone which convey the "extremely high spatial and temporal precisions of synaptic signal transduction". The neurotransmitter release is preceded by multi-stage processes in the active zone in the course of which the neutron provides the neurotransmitters in so-called vesicles.

An exact image of the spatial distribution of the active zone's molecular constituents and thus information regarding the organisational principles has been the goal of Kittel's research for a long time, because it is these properties which are decisive for the function of the active zone. Collaborating with fellow Würzburg scientists, he has now moved closer to this goal.

Super-resolution optical microscopy

The breakthrough came with the cooperation with Professor Markus Sauer, head of the Department of Biotechnology and Biophysics at University of Würzburg's Biocenter. Together with his team, Sauer developed a method capable of delivering the desired images. Its name: dSTORM – direct Stochastic Optical Reconstruction Microscopy. A special form of high-resolution fluorescence microscopy, it enables imaging cellular structures and molecules with a ten- to hundred-fold increase in resolution compared to standard optical microscopy. The scale of the imaged objects is in the range of a few nanometres – that is, millionths of millimetres.

Electrophysiological measurements at the neurons of Drosophila combined with the dSTORM images then delivered the information the scientist had been looking for: the relationship between the spatial arrangement of special proteins at nanoscale and the functional properties of the active zone.

In fact, this enabled the researchers to count the copies of the so-called "Bruchpilot" protein in the active zones and thereby work out quantitative structure-function relationships. "The analysis of the spatial organisation of molecules provides us information regarding the functional mechanisms of the active zone and helps us shed light on the basic mechanisms of brain function," is how the researchers interpret the result.

Quantitative super-resolution imaging of Bruchpilot distinguishes active zone states. Nadine Ehmann, Sebastian van de Linde, Amit Alon, Dmitrij Ljaschenko, Xi Zhen Keung, Thorge Holm, Annika Rings, Aaron DiAntonio, Stefan Hallermann, Uri Ashery, Manfred Heckmann, Markus Sauer & Robert J. Kittel, Nature Communications. DOI: 10.1038/ncomms5650

Contact

Dr. Robert Kittel, Telephone: +49 931 31-86046, robert.kittel@uni-wuerzburg.de
Prof. Dr. Markus Sauer, Telephone: +49 931-88687, m.sauer@uni-wuerzburg.de

Robert Emmerich | Julius-Maximilians-Universität Würzburg
Further information:
http://www.uni-wuerzburg.de

More articles from Life Sciences:

nachricht How to become a T follicular helper cell
31.07.2015 | La Jolla Institute for Allergy and Immunology

nachricht Heating and cooling with light leads to ultrafast DNA diagnostics
31.07.2015 | University of California - Berkeley

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Quantum Matter Stuck in Unrest

Using ultracold atoms trapped in light crystals, scientists from the MPQ, LMU, and the Weizmann Institute observe a novel state of matter that never thermalizes.

What happens if one mixes cold and hot water? After some initial dynamics, one is left with lukewarm water—the system has thermalized to a new thermal...

Im Focus: On the crest of the wave: Electronics on a time scale shorter than a cycle of light

Physicists from Regensburg and Marburg, Germany have succeeded in taking a slow-motion movie of speeding electrons in a solid driven by a strong light wave. In the process, they have unraveled a novel quantum phenomenon, which will be reported in the forthcoming edition of Nature.

The advent of ever faster electronics featuring clock rates up to the multiple-gigahertz range has revolutionized our day-to-day life. Researchers and...

Im Focus: Superfast fluorescence sets new speed record

Plasmonic device has speed and efficiency to serve optical computers

Researchers have developed an ultrafast light-emitting device that can flip on and off 90 billion times a second and could form the basis of optical computing.

Im Focus: Unlocking the rice immune system

Joint BioEnergy Institute study identifies bacterial protein that is key to protecting rice against bacterial blight

A bacterial signal that when recognized by rice plants enables the plants to resist a devastating blight disease has been identified by a multi-national team...

Im Focus: Smarter window materials can control light and energy

Researchers in the Cockrell School of Engineering at The University of Texas at Austin are one step closer to delivering smart windows with a new level of energy efficiency, engineering materials that allow windows to reveal light without transferring heat and, conversely, to block light while allowing heat transmission, as described in two new research papers.

By allowing indoor occupants to more precisely control the energy and sunlight passing through a window, the new materials could significantly reduce costs for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Euro Bio-inspired - International Conference and Exhibition on Bio-inspired Materials

23.07.2015 | Event News

Clash of Realities – International Conference on the Art, Technology and Theory of Digital Games

10.07.2015 | Event News

World Conference on Regenerative Medicine in Leipzig: Last chance to submit abstracts until 2 July

25.06.2015 | Event News

 
Latest News

Tool making and additive technology exhibition: Fraunhofer IPT at Formnext

31.07.2015 | Trade Fair News

First Siemens-built Thameslink train arrives in London

31.07.2015 | Transportation and Logistics

California 'rain debt' equal to average full year of precipitation

31.07.2015 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>