Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How colors enter the world of the fly

10.12.2013
Tasty bread crumb or just a boring dust grain? Color vision facilitates the recognition of objects. Neurobiologists at the Bernstein Center Munich now discover a new pathway for color in the fly's compound eye and help to unravel color perception in insects.

To distinguish colors, the brain compares signals from sensory cells that are activated by light of different wavelengths. But how does color information reach a fly’s brain? Insects possess compound eyes, which are composed of many individual eye units, so-called ommatidia.


To detect an object on the basis of color, flies use both inner and outer receptor cells of the innumerable ommatidia in the flies' compound eyes, as Bernstein scientists have now discovered.
Pavel Masek/Bernstein Koordinationsstelle, 2013

A single ommatidium consists of eight light-sensitive photoreceptor cells. Six of them are arranged in a ring, with the two remaining cells located in its center. In flies, the six outer receptor cells respond to light over a broad range of wavelengths. Since the perception of color depends on the processing of specific wavelength regions, researchers assumed that these receptors are mainly responsible for motion perception.

In contrast, the two inner photoreceptors are sensitive to light of single narrow wavelength regions—and may therefore pass on precise information about colors. So far, they have been considered to be the exclusive source of color vision in flies.

Neuroscientists at the Bernstein Center Munich, the Max Planck Institute of Neurobiology in Martinsried, and the LMU Munich now discovered that this assumption needs to be revised. "The outer photoreceptors contribute to color discrimination of the fly as well," explains Thomas Wachtler, one of the researchers involved in the study. Using a computer model, the biologists mimicked the processing of photoreceptor signals in the fly eye—and realized that the wavelength sensitivity of the outer photoreceptors must be taken into account in order to obtain the fly's color discrimination abilities.

To support their theoretical results with experimental data, the researchers selectively controlled photoreceptor function in genetically manipulated flies. In this way, they obtained flies that possessed only one of the two color-specific inner receptor cells besides the outer receptor cells. Yet, the flies were able to distinguish two colors. "This indicates that the brain draws on information from both inner and outer photoreceptors for the color comparison," explains Christopher Schnaitmann, first author of the study. The assumption was confirmed when the scientists inhibited the activity of nerve cells that convey signals from the outer receptor cells to the brain: the flies' ability to perceive color differences was severely impaired.

The outer photoreceptors thus seem to be true multitaskers, contributing to both motion and color vision in the fly. Their dual role makes sense in small animals: it ensures that despite a limited number of neurons, flies still have complex visual skills—and may easily distinguish a bread crumb from a dust grain.

The Bernstein Center Munich 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 170 million Euros. The network is named after the German physiologist Julius Bernstein (1835-1917).

Contact:
Dr. Hiromu Tanimoto
Max-Planck-Institut für Neurobiologie
Am Klopferspitz 18
82152 Martinsried
Tel: +49 (0)89 8578 3492
Email: hiromut@neuro.mpg.de
PD Dr. Thomas Wachtler
Ludwig-Maximilians-Universität
Department Biology II 

Grosshadernerstr. 2 

82152 Martinsried
Tel: +49 (0)89 2180 74810 

Email: wachtler@bio.lmu.de
Original publication:
C. Schnaitmann, C. Garbers, T. Wachtler & H. Tanimoto (2013): Color discrimination with broadband photoreceptors. Current Biology, 23(23): 2375-82.

http://dx.doi.org/10.1016/j.cub.2013.10.037

Weitere Informationen:

http://www.neuro.mpg.de/tanimoto website Hiromu Tanimoto
http://neuro.bio.lmu.de/research_groups/res-wachtler_th website Thomas Wachtler
http://www.bccn-munich.de Bernstein Center Munich
http://www.uni-muenchen.de LMU Munich
http://wwww.nncn.de National Bernstein Network Computational Neuroscience

Mareike Kardinal | idw
Further information:
http://wwww.nncn.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 >>>