Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Locating ground zero: How the brain’s emergency workers find the disaster area

25.05.2012
Like emergency workers rushing to a disaster scene, cells called microglia speed to places where the brain has been injured, to contain the damage by ‘eating up’ any cellular debris and dead or dying neurons.

Scientists at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, have now discovered exactly how microglia detect the site of injury, thanks to a relay of molecular signals. Their work, published today in Developmental Cell, paves the way for new medical approaches to conditions where microglia’s ability to locate hazardous cells and material within the brain is compromised.

“Considering that they help keep our brain healthy, we know surprisingly little about microglia,” says Francesca Peri, who led the work. “Now, for the first time, we’ve identified the mechanism that allows microglia to detect brain injury, and how that emergency call is transmitted from neuron to neuron.”

When an emergency occurs, cries can alert bystanders, who will dial the emergency number. A call will go out over the radio, and ambulances, police or fire engines in the area will respond as needed. In the brain, Peri and colleagues found, injured neurons send out their own distress cry: they release a molecule called glutamate. Neighbouring neurons sense that glutamate and respond by taking up calcium. As glutamate spreads out from the injury site, this creates a wave of calcium swallowing. Along that wave, as neurons take up calcium they release a third molecule, called ATP. When the wave comes within reach, a microglial cell detects that ATP and takes it as a call to action, moving in that direction – essentially tracing the wave backwards until it reaches the injury.

Scientists knew already that microglia can detect ATP, but this molecule doesn’t last long outside of cells, so there were doubts about how ATP alone could be a signal that carried far enough to reach microglia located far from the site of injury. The trick, as Peri and colleagues discovered, is the long-lasting glutamate-driven calcium wave that can travel the length of the brain. Thanks to this wave, the ATP signal is not just emitted by the injured cells, but is repeatedly sent out by the neurons along the way, until it reaches microglia.

Dirk Sieger and Christian Moritz in Peri’s lab took advantage of the fact that zebrafish have transparent heads, which allow scientists to peer down a microscope straight into the fish’s brain. They used a laser to injure a few of the fish’s brain cells, and watched fluorescently-labelled microglia move in on the injury. When they genetically engineered zebrafish to make neurons’ calcium levels traceable under the microscope, too, the scientists were able to confirm that when the calcium wave reached microglia, these cells immediately started moving toward the injury.

Knowing all the steps in this process, and how they feed into each other, could help to design treatments to improve microglia’s detection ability, which go awry in conditions such as Alzheimer’s and Parkinson’s diseases.

Published online in Developmental Cell on 24 May 2012.
The work will also be featured in a Cell PaperFlick video.
Policy regarding use
EMBL press and picture releases including photographs, graphics and videos are copyrighted by EMBL. They may be freely reprinted and distributed for non-commercial use via print, broadcast and electronic media, provided that proper attribution to authors, photographers and designers is made.
Sonia Furtado Neves
EMBL Press Officer
Meyerhofstr. 1, 69117 Heidelberg, Germany
Tel.: +49 (0)6221 387 8263
Fax: +49 (0)6221 387 8525
sonia.furtado@embl.de

Sonia Furtado Neves | EMBL Research News
Further information:
http://www.embl.org

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 >>>