Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The architects of the brain

26.10.2011
Bochum’s neurobiologists have found that certain receptors for the neurotransmitter glutamate determine the architecture of nerve cells in the developing brain.

Individual receptor variants lead to especially long and branched processes called dendrites, which the cells communicate with. The researchers also showed that the growth-promoting property of the receptors is linked to how much calcium they allow to flow into the cells. “These results allow insights into the mechanisms with which nerve cells connect during development”, says Prof. Dr. Petra Wahle from the RUB Working Group on Developmental Neurobiology. The scientists report in Development.


Growth of dendritic processes: When glutamate docks on to the AMPA receptor, calcium ions flow into the nerve cell. They cause the production of special growth molecules which trigger the extension and branching of the dendrites. AG Entwicklungsneurobiologie


Effect of a glutamate receptor: The researchers compared the architecture of special inhibitory nerve cells (interneurons) with low and high numbers of a specific glutamate receptor (GluA1(Q)-flip). Cells with a high number of GluA1(Q)-flip (right) had longer and more branched dendritic processes than cells in which the receptor only occurred rarely (left). AG Entwicklungsneurobiologie

It all depends on a few amino acids

“Nerve cells communicate with chemical and electrical signals”, explains Wahle. “The electrical activity controls many developmental processes in the brain, and the neurotransmitter glutamate plays a decisive role in this.” In two different cell classes in the cerebral cortex of rats, the researchers studied the nine most common variants of a glutamate receptor, the so-called AMPA receptor. When glutamate docks on to this receptor, calcium ions flow into the nerve cells either directly through a pore in the AMPA receptor or through adjacent calcium channels. Depending on the variant, AMPA receptors consist of 800-900 amino acid building blocks, and already the exchange of one amino acid has important consequences for the calcium permeability. Among other things, calcium promotes the growth of new dendrites.

Different cell types, different mechanisms

One at a time, the Bochum team introduced the nine AMPA receptor variants into the nerve cells and observed the impact on the cell architecture. In several cases, this resulted in longer dendrites with more branches. This pattern was demonstrated both for several receptor variants that allow calcium ions to flow directly into the cell through a pore and for those that activate adjacent calcium channels. “It was surprising that in the two cell classes studied, different receptor variants triggered the growth of the dendrites”, says Dr. Mohammad Hamad from the Working Group on Developmental Neurobiology. “In the inhibitory interneurons, only one of the nine variants was effective. Calcium signals are like a toolbox. However, different cell classes in the cerebral cortex make use of the toolbox in different ways.”

Bibliographic record

Hamad, M. I., Ma-Hogemeier, Z. L., Riedel, C., Conrads, C., Veitinger, T., Habijan, T., Schulz, J. N., Krause, M., Wirth, M. J., Hollmann, M., Wahle, P. (2011) Cell class-specific regulation of neocortical dendrite and spine growth by AMPA receptor splice and editing variants. Development 138, 4301-4313, doi: 10.1242/dev.07107

Further information

Prof. Dr. Petra Wahle, AG Entwicklungsneurobiologie, Faculty of Biology and Biotechnology at the Ruhr-Universität, 44780 Bochum, Tel.: 0234/32-24367

wahle@neurobiologie.ruhr-uni-bochum.de

Dr. Josef König | idw
Further information:
http://www.ruhr-uni-bochum.de/

More articles from Life Sciences:

nachricht How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH

nachricht A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

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 we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>