Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Less is more – Grasshoppers detect species-specific songs with few cells

12.08.2011
Our senses are constantly flooded with stimuli. In order to distinguish important from unimportant information, our senses already provide a valuable preprocessing step for the brain. Even just a few cells suffice in order to process complex stimuli, as scientists from the Bernstein Center Berlin and the Humboldt Universität zu Berlin showed in the journal PNAS.

They investigated how the auditory system of grasshoppers recognizes species-specific courtship songs and found that only three cellular interconnections are needed for song identification. Furthermore, it does not matter that the signals transduced to the brain are far less precise than the input signals.


The ears of grasshoppers are located in the abdomen; neurons that are also important for sound processing are in the thorax region. Only highly filtered information reaches the brain. © Sandra Wohlgemuth

Millions of stimuli affect us, but only a fraction of these is important to us. The stimuli are filtered by the sensory organs and preprocessed so that our brain is able to track what is important without becoming overwhelmed. The retina, for instance, does not only send single pixel information to the brain, but also information about movements and edges. For this purpose, a large network of thousands of cells is necessary. However, in many animals the neuronal networks of the sensory organs are much more simply constructed. Researchers led by Prof. Bernhard Ronacher, Prof. Susanne Schreiber and Dr. Sandra Wohlgemuth of the Bernstein Center and the Humboldt Universität in Berlin wondered how efficiently simple networks can perform the preprocessing of complex stimuli.

Therefore, they examined the auditory system of grasshoppers, which is important for the recognition of species-specific courtship songs. The studied neurons are found in the thoracic ganglia of the animals. The researchers discovered to their surprise that after three cellular processing steps the information was already heavily modified, and, above all, temporally inaccurate. However, the neuronal signals that were transmitted to the brain contained the essential information about song features.

The courtship songs of different grasshopper species are characterized by alternating sounds and pauses. The activity of the sensory cells that sit in the ear on the abdomen of the animals was precisely temporally coupled with the incoming stimulus patterns. This allows the animals a very accurate classification of the patterns of courtship songs. But already the following cells showed a specific pattern of activity that forwarded only a fraction of the information. “At the beginning, we were very surprised that the network destroys that important precision,” says first author Jan Clemens. However, their analysis shows the reason for the change in signals. “While at the beginning of processing, most information lies in the precise timing of neuronal signals, the output signals are rather a yes-no answer,” says group leader Susanne Schreiber. Thus, many details are lost on the way to the grasshoppers’ brain, but the essential content about song features is much more readily available to the animal.

Thus, this small network also matches the prediction that information processing should be highly efficient in nervous systems in order to survive in evolution. For the next step, the scientists in Berlin aim to rebuild this neuronal network on the computer in order to understand such important data processing more thoroughly.

The Bernstein Center Berlin is part of the National Bernstein Network Computational Neuroscience (NNCN) in Germany. The NNCN was established by the German Federal Ministry of Education and Research with the aim of structurally interconnecting and developing German capacities in the new scientific discipline of computational neuroscience. It was named in honor of the German physiologist Julius Bernstein (1835–1917).

Original publication:
Clemens J, Kutzki O, Ronacher B, Schreiber S*, Wohlgemuth S* (2011): Efficient transformation of an auditory population code in a small sensory system, PNAS doi:10.1073/pnas.1104506108, *equal contribution

http://www.pnas.org/content/early/2011/08/03/1104506108.abstract

Contact person:
Professor Dr. Susanne Schreiber
s.schreiber@hu-berlin.de
Institute for Theoretical Biology
Humboldt-Universität zu Berlin
Invalidenstr. 43
10115 Berlin
Phone: ++49-30-2093 8652
Jan Clemens
clemensjan@gmail.com
Institute for Biology / Behavioral Physiology Group
Humboldt-Universität zu Berlin
Invalidenstraße 43
10115 Berlin
Phone: ++49-30-2093-8777

Johannes Faber | idw
Further information:
http://www.bccn-berlin.de/
http://www.nncn.de/
http://www.hu-berlin.de/

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

German Federal Government Promotes Health Care Research

29.03.2017 | Awards Funding

Periodic ventilation keeps more pollen out than tilted-open windows

29.03.2017 | Health and Medicine

Researchers discover dust plays prominent role in nutrients of mountain forest ecoystems

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>