Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fruit fly studies shed light on adaptability of nerve cells

17.04.2015

An international team of researchers at German Center for Neurodegenerative Diseases (DZNE) and Tokyo Institute of Technology (Tokyo Tech) have revealed in a collaborative study - published today in NEURON, that neurons in the eye change on the molecular level when they are exposed to prolonged light. The researchers could identify that a feedback signalling mechanism is responsible for these changes. The innate neuronal property might be utilized to protect neurons from degeneration or cell death in the future.

Changes in the functional connections between neurons – ‘synapses’ – contribute to our ability to adapt to environmental changes. However until now, little was known about the signalling underlying such ‘synaptic plasticity’.


Schematic of the Drosophila visual system

Prof. Dr. Takashi SUZUKI / TokyoTech

Now, investigations of fruit flies by researchers at the German Center for Neurodegenerative Diseases (DZNE), Tokyo Tech, the National Institute of Genetics in Japan, and the European Neuroscience Institute in Germany reveal details of the mechanisms behind synaptic plasticity.

“The synaptic changes that we have identified might reflect an innate neuronal property that leads to protection from excessive stimuli,” explains Dr. Atsushi Sugie, the study's lead author and Postdoc at DZNE. “By enhancing this property, we might be able to protect neurons from degeneration or cell death.”

Recent studies have suggested that changes in a region at the presynaptic membrane, described as the active zone, control synapse function. The research teams based in Germany and Japan exposed living fruit flies – the commonly studied Drosophila – to different light regimes and then compared the active zones in the photoreceptors.

T-shaped structures at the presynaptic membrane tether synaptic vesicles and control the release of neurotransmitters to the postsynaptic neuron. By tagging proteins that are crucial to these T-shaped structures the researchers revealed a drop in a subset of active zone proteins, while others remained unchanged. Further, they found that corresponding to the loss of structural proteins, the number of T-shaped structures was also reduced.

The researchers were also able to identify that a feedback mechanism was responsible for these changes and that it relied on the signalling protein Wnt. The results contribute to a better understanding of the molecular mechanisms underlying brain functions such as learning and memory. Future work may investigate how modifying the Wnt signal can be used to manipulate synaptic plasticity, with possible therapeutic applications for neurodegenerative or mental diseases.

Background

Synapses

Synapses allow chemical signals to pass between neurons so that information can travel around the nervous system. Chemical signals are passed by the presynaptic release of neurotransmitters by synaptic vesicles. The neurotransmitters are received by postsynaptic receptors allowing the signal to pass from neuron to target neuron.

Repetitive or prolonged stimuli can lead to short- or long-term changes at synapses, affecting how they transmit signals and supporting plastic changes in the function of the nervous system, including learning and memory or the ability to adapt to environmental changes.

The role of proteins

Previous studies have identified that the probability of neurotransmitter release is strongly correlated with the levels of certain proteins at the active zone region of the pre-synaptic membrane. In addition, the localization of these proteins depends on neural activity. The present study reveals that the molecular composition of synapses can be modulated in living organisms exposed to sustained environmental stimuli.

Study details

Sugie and her colleagues maintained Drosophila fruit flies that had just entered the adult stage of their life cycle in one of three light regimes: constant light; constant dark; and 12 hours light with 12 hours dark. The light used was mild to avoid retinal degeneration. Observations of fluorescently-tagged active zone protein Bruchpilot showed that while this protein was initially localised at discrete points representing active zones, prolonged exposure to light caused delocalization, which was reversed when the flies were returned to darkness.

A number of proteins have been associated with the structure of the active zone and the T-shaped structures that tether the synaptic vesicles. Although a subset of proteins was not affected, the researchers observed changes comparable to the loss of Bruchpilot in other proteins with similar functions, as well as re-organization of the microtubules.

According to the researchers the study suggests an accessible paradigm for assessing synaptic plasticity in neuronal synapses, as opposed to neuro-muscular synapses. They also emphasise how in their work they monitor synaptic plasticity with an optical microscope by tagging proteins with fluorescent molecules without the need for an electron microscope.

Reference

Authors: Atsushi Sugie, Satoko Hakeda-Suzuki, Emiko Suzuki, Marion Silies, Mai Shimozono, Christoph Mohl, Takashi Suzuki* and Gaia Tavosanis*
*Co-corresponding authors
Title of original paper: Molecular Remodelling of the Presynaptic Active Zone of Drosophila Photoreceptors via Activity-Dependent Feedback
Journal: Neuron 86, 1-15, May 6, 2015
Published on line at 6:00 pm 16th April 2015, Central European Summer time.
Published on line at 1:00 am 17th April 2015, Japan standard time.
DOI: 10.1016/j.neuron.2015.03.046

Press contact

Ms Ulrike Koch
German Center for Neurodegenerative Diseases (DZNE)
Public and Political Affairs
Email: ulrike.koch@dzne.de
URL: http://www.dzne.de
Tel: +49-228-43302-263

Ms Asuka Suzuki
Research Communication
Tokyo Institute of Technology
Email: media@jim.titech.ac.jp
URL: http://www.titech.ac.jp/english/
Tel: +81-3-5734-2975

About the German Center for Neurodegenerative Diseases

The German Center for Neurodegenerative Diseases (DZNE) investigates the causes of diseases of the nervous system and develops strategies for prevention, treatment and care. It is an institution of the Helmholtz Association of German Research Centres with sites in Berlin, Bonn, Dresden, Göttingen, Magdeburg, Munich, Rostock/Greifswald, Tübingen and Witten. The DZNE cooperates closely with universities, their clinics and other research facilities. www.dzne.de, www.twitter.com/dzne_en.

About Tokyo Institute of Technology

As one of Japan’s top universities, Tokyo Institute of Technology seeks to contribute to civilization, peace and prosperity in the world, and aims at developing global human capabilities par excellence through pioneering research and education in science and technology, including industrial and social management. To achieve this mission, we have an eye on educating highly moral students to acquire not only scientific expertise but also expertise in the liberal arts, and a balanced knowledge of the social sciences and humanities, all while researching deeply from basics to practice with academic mastery. Through these activities, we wish to contribute to global sustainability of the natural world and the support of human life. http://www.titech.ac.jp/english/

Weitere Informationen:

http://www.dzne.de/en/about-us/public-relations/meldungen/2015/press-release-no-...

Ulrike Koch | idw - Informationsdienst Wissenschaft

Further reports about: DZNE fly fruit flies nerve cells nervous system plasticity protein proteins stimuli structures synaptic vesicles

More articles from Life Sciences:

nachricht Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz

nachricht Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>