Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The brain lights up

27.09.2010
The dynamic activity of electrical signals in neuronal populations can now be visualized with a powerful tool

Information processing in the brain relies on the coordinated activity between populations of different types of neurons, each with distinct electrical properties and connections. Understanding how complex neuronal circuitry processes information is challenging, as it requires measuring the activity of groups of specified cells.

Thomas Knöpfel of the RIKEN Brain Science Institute, Wako, and his colleagues have developed a genetically encoded voltage sensor that can be used to probe the electrical of activity from selected populations of defined neurons within the brains of living animals1. The sensor is based on voltage-sensitive proteins that insert themselves into the membrane of genetically targeted nerve cells and emit a fluorescent signal in response to the changes in membrane voltage that occur during neuronal activity.

Knöpfel’s group validated the sensor by introducing it into cultured mouse hippocampal neurons. By inserting electrodes into the cells and observing them under the microscope, they found that single spontaneous nervous impulses were accompanied by an increase in yellow fluorescence.

The same results were obtained in brain slices prepared from mice transfected with DNA encoding the sensor while still in the womb. These experiments also showed that the sensor is capable of detecting circuit activity in the slices. When nervous impulses were induced in specified cells using electrodes, fluorescent signals were observed in the cells connected to them.

Finally, the researchers demonstrated that the sensor can detect the activity of specific groups of cells in the brains of live mice in response to natural sensory stimuli. Again, they transfected embryonic mice with the sensor, targeting a brain region called the barrel cortex, which receives information from the whiskers.

When the mice became adults, the researchers stimulated their whiskers and monitored activity in the barrel cortex through thinned regions of the animals’ skulls. Deflection of individual whiskers was found to produce fluorescent signals in the corresponding area of the cortex.

Other optical methods available for monitoring neuronal activity have disadvantages. Voltage-sensitive dyes can be toxic to cells, while genetically encoded calcium indicators, which fluoresce in response to the localized calcium signals characteristic of neuronal activity, can interfere with signaling pathways by buffering calcium and provide information only on a slower time scale. The voltage sensor developed by Knöpfel and his colleagues therefore improves on them.

“This will facilitate the investigation of fundamental questions of information processing in the brain,” says Knöpfel, “and will also be applicable to directly visualize cognitive function.”

The corresponding author for this highlight is based at the Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute

Journal information
1. Akemann, W., Mutoh, H., Perron, A., Rossier, J. & Knöpfel, T. Imaging brain electric signals with genetically targeted voltage-sensitive fluorescent proteins. Nature Methods 7, 643–649 (2010).

gro-pr | Research asia research news
Further information:
http://www.rikenresearch.riken.jp/eng/research/6402
http://www.researchsea.com

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>