Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Communication without detours

22.09.2014

Certain nerve cells take a shortcut for the transmission of information: signals are not conducted via the cell`s center, but around it like on a bypass road. The previously unknown nerve cell shape is now presented in the journal "Neuron" by a research team from Heidelberg, Mannheim and Bonn.

Nerve cells communicate by using electrical signals. Via widely ramified cell structures—the dendrites—, they receive signals from other neurons and then transmit them over a thin cell extension—the axon—to other nerve cells. Axon and dendrites are usually interconnected by the neuron’s cell body. A team of scientists at the Bernstein Center Heidelberg-Mannheim, Heidelberg University, and the University of Bonn has now discovered neurons in which the axon arises directly from one of the dendrites. Similar to taking a bypass road, the signal transmission is thus facilitated within the cell.


A neuron in which the axon originates at a dendrite. Signals arriving at this dendrites become more efficiently forwarded than signals input elsewhere.

Copyright: Alexei V. Egorov, 2014

“Input signals at this dendrite do not need not be propagated across the cell body,” explains Christian Thome of the Bernstein Center Heidelberg-Mannheim and Heidelberg University, one of the two first authors of the study. For their analyses, the scientists specifically colored the places of origin of axons of so-called pyramidal cells in the hippocampus. This brain region is involved in memory processes. The surprising result: “We found that in more than half of the cells, the axon does not emerge from the cell body, but arises from a lower dendrite,” Thome says.

The researchers then studied the effect of signals received at this special dendrite. For this purpose, they injected a certain form of the neural transmitter substance glutamate into the brain tissue of mice that can be activated by light pulses. A high-resolution microscope allowed the neuroscientists to direct the light beam directly to a specific dendrite. By the subsequent activation of the messenger substance, they simulated an exciting input signal.

“Our measurements indicate that dendrites that are directly connected to the axon, actively propagate even small input stimuli and activate the neuron,” says second first author Tony Kelly, a member of the Sonderforschungsbereich (SFB) 1089 at the University of Bonn. A computer simulation of the scientists predicts that this effect is particularly pronounced when the information flow from other dendrites to the axon is suppressed by inhibitory input signals at the cell body.

“That way, information transmitted by this special dendrite influences the behavior of the nerve cell more than input from any other dendrite,” Kelly says. In a future step, the researchers attempt to figure out which biological function is actually strengthened through the specific dendrite—and what therefore might be the reason for the unusual shape of these neurons.

The Bernstein Center Heidelberg-Mannheim is part of the National Bernstein Network Computational Neuroscience in Germany. With this funding initiative, the German Federal Ministry of Education and Research (BMBF) has supported the new discipline of Computational Neuroscience since 2004 with over 180 million Euros. The network is named after the German physiologist Julius Bernstein (1835-1917).

The SFB 1089 ‘Synaptic Micronetworks in Health and Disease’ is a collaborative research centre in Bonn with partners in Israel. Members of the research group investigate how neurons interact within networks, and the translation of neuronal network activity to mammalian and human behavior. This SFB was inaugurated in October 2013 with the support of the German Research Foundation (DFG).

Contact:

Dr. Alexei V. Egorov
Institute of Physiology and Pathophysiology
Medical Faculty of Heidelberg University
Im Neuenheimer Feld 326
69120 Heidelberg
Tel: +49 (0) 6221 544053
Email: alexei.egorov@urz.uni-heidelberg.de

Prof. Dr. med. Andreas Draguhn
Institute of Physiology and Pathophysiology
Medical Faculty of Heidelberg University
Im Neuenheimer Feld 326
69120 Heidelberg
Tel: +49 (0) 6221 544056
Email: andreas.draguhn@physiologie.uni-heidelberg.de

Dr. Tony Kelly
Laboratory of Experimental Epileptology and Cognition Research
University of Bonn Medical Center
Sigmund-Freud Str. 25
53127 Bonn
Tel: +49 (0) 228 6885 276
Email: tony.kelly@ukb.uni-bonn.de

Prof. Dr. med. Heinz Beck
Laboratory of Experimental Epileptology and Cognition Research
University of Bonn Medical Center
Sigmund-Freud Str. 25
53127 Bonn
Tel: +49 (0) 228 6885 270
Email: heinz.beck@ukb.uni-bonn.de

Original publication:

C. Thome, T. Kelly, A. Yanez, C. Schultz, M. Engelhardt, S. B. Camebridge, M. Both, A. Draguhn, H. Beck and A. V. Egorov (2014): Axon-Carrying Dendrites Convey Privileged Synaptic Input in Hippocampal Neurons. Neuron, 83, 1418-1430.
doi: 10.1016/j.neuron.2014.08.013

siehe auch Kommentar: P. Kaifosh and A. Losonczy (2014). Neuron, 83, 1231-1233.

Weitere Informationen:

http://www.medizinische-fakultaet-hd.uni-heidelberg.de/Draguhn-Andreas-Prof-Dr.1... webpage Andreas Draguhn
http://www.uni-heidelberg.de University Heidelberg
http://www.meb.uni-bonn.de/agBeck Laboratory for Experimental Epileptology, University of Bonn
http://sfb1089.de Sonderforschungsbereich 1089 at University of Bonn
http://www.bccn-heidelberg-mannheim.de Bernstein Center Heidelberg-Mannheim
http://www.nncn.de/en National Bernstein Network Computational Neuroscience

Mareike Kardinal | idw - Informationsdienst Wissenschaft

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

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 Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>