Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Electric Signals Amplify Weak Olfactory Stimuli in the Nose

01.02.2011
Scientists at Heidelberg University decipher functioning of olfactory cells

The human olfactory system possesses a special electric amplification mechanism that enables olfactory cells to respond even to extremely weak stimuli.

Scientists at Heidelberg University headed by physiologist Prof. Dr. Stephan Frings have now established how this mechanism works. Crucial is the role played by chloride ions stored in the sensory cilia of the nose. As soon as the olfactory receptors in the sensory cilia detect odorants, the chloride ions are immediately discharged. This process generates strong electric signals that pass on the relevant olfactory information to the brain.

Our noses detect a huge variety of odorants in the air we breathe. The olfactory system is confronted with an immense diversity of chemical compounds. The air in a room where a coffee machine is making coffee, where there are plants on the window-sill and people walking in and out contains thousands of different odorants. But our olfactory system finds this apparent chaos easy to deal with. It unerringly identifies the smell of coffee, although that smell alone is made up of over 800 different odorants. For this purpose the olfactory cells in the nose are equipped with olfactory receptors, proteins presented to the inhaled air on fine sensory cilia by the olfactory cells.

Up to now, research on olfactory cells and their receptors has been dogged by one unanswered question. The concentration of individual odorants in the nose – i.e. the number of molecules of a given odorant per cubic centimetre of ambient air – is very low. In addition, olfactory receptors have proved to be relatively insensitive, only responding very weakly to low odorant concentrations. So how can the key function of our highly sensitive olfactory system be performed by receptors that are themselves remarkably insensitive? The answer lies in the electric amplification mechanism for the olfactory cells deciphered by Prof. Frings and his team at Heidelberg University’s Centre for Organismal Studies.

The sensory cilia of the olfactory cells prepare themselves for the job in a special way. A protein complex pumps chloride ions into the interior of the sensory cilia, thus making them into well-filled chloride stores. When an olfactory stimulus occurs, another protein swings into action, a chloride channel that the sensory cilia possess many copies of in their external membranes. These chloride channels remain closed as long as the olfactory cell is at rest. When an olfactory stimulus is registered, the weak response of the olfactory receptors immediately opens all the channels. The release of negatively charged chloride ions causes a loading inversion in the olfactory cell. This in its turn produces strong electric signals that are conveyed to the brain with the olfactory information.

For more information, go to http://www.molekulare-physiologie.de/index_en.html.

Original publication:
T. Hengl, H. Kaneko, K. Dauner, K. Vocke, S. Frings, F. Möhrlen: Molecular Components of Signal Amplification in Olfactory Sensory Cilia. PNAS (30 March 2010) 107:6052-6057, doi: 10.1073/pnas.0909032107
Contact:
Prof. Dr. Stephan Frings
Centre for Organismal Studies
Department of Molecular Animal Physiology
phone: +49 6221 545661
s.frings@zoo.uni-heidelberg.de
Communications and Marketing
Press Office, phon +49 6221 543211
presse@reaktorat.uni-heidelberg.de

Marietta Fuhrmann-Koch | idw
Further information:
http://www.uni-heidelberg.de
http://www.molekulare-physiologie.de/index_en.html

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>