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 Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

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

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>