Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Optogenetic probes to image brain electrical activity in laboratory mice

14.07.2010
RIKEN scientists have developed a genetically-encoded fluorescent sensor that can act as a direct optical indicator of signaling activity in the living brain.

This powerful tool, described in a new article from Nature Methods, promises to help neuroscientists identify and monitor the behavior of neural circuits involved in motor activity, sensory perception and other functions.

Researchers have historically analyzed the complex electrical activity of the brain using an invasive approach involving tiny electrodes, whose large size relative to individual nerve cells has limited the number of locations from which neuronal activity can be sampled. Optimal imaging methods overcome this limitation with molecular size probes that transform the electrical signals into an optical reporter signal.

The voltage-sensitive fluorescent proteins (VSFPs) developed by Thomas Knöpfel’s team at the RIKEN Brain Science Institute represent an important step in this direction. These are engineered proteins that reside within the membranes of neurons, each of which is fused to two different fluorescent proteins. Whenever a neuron receives a stimulatory signal, the resulting change in voltage potential in the cell membrane causes the VSFPs to rearrange into a configuration that causes a readily detectable change in the optical signal generated by the VSFP, in a phenomenon known as Förster Resonance Energy Transfer.

Knöpfel’s laboratory pionered the development of these sensors for more than 10 years but up to now the function of these probes was only demonstrated by recording electrical activity from 2-dimensional networks of cultured nerve cells. In the latest edition of Nature Methods, the team presents the first experimental confirmation that these probes are able to report electrical activity of nerve cells in the brains of living mice. The researchers used genetically modified mice to localize the VSFP probe within specific subsets of cortical neurons within a brain area called the somatosensory cortex. Each mouse whisker is wired to discrete neural circuits in the somatosensory cortex, and the researchers found that they could readily detect changes in the membrane voltage of these circuit elements as each whisker was manipulated. Based on these experiments, they were essentially able to reconstruct maps of the cell populations that operate as ‘receptive areas’ for individual whiskers.

Being genetically encoded, VSFPs offer several advantages over other commonly-used approaches to monitoring neuronal activity. They can essentially be ‘programmed’ for selective expression within specific subtypes of neurons or particular regions of the brain, and could be used to chart long-range neural circuits extending over considerable distances, unlike fluorescent dyes that label cells non-specifically and can only be applied within a relatively limited volume of the brain. Other genetically-encoded sensors have been developed that respond to calcium flux in the immediate aftermath of neuronal firing, but these represent indirect indicators and generally respond more slowly to neuronal activity.

Given the high degree of spatial and temporal resolution displayed by the VSFPs in this study, Knöpfel is confident that they will prove a useful tool for researchers hoping to understand how patterns of neuronal activity correlate with behavior or physiological changes in the living brain. “The ability of VSFPs to report faster signals, along with genetic targeting, will allow new approaches to the study of the dynamic interaction of assemblies of neurons,” he says. “This will facilitate the investigation of fundamental questions of information processing in the brain, such as the circuit operations involved in sensing our environment and generation of body movements, but will also be applicable to directly visualize cognitive functions.”

For more information, please contact:

Dr. Thomas Knöpfel
Laboratory for Neuronal Circuit Dynamics
RIKEN Brain Science Institute
Tel: +81-(0)48-467-9740 / Fax: +81-(0)48-467-9739
Ms. Tomoko Ikawa (PI officer)
Global Relations Office
RIKEN
Tel: +81-(0)48-462-1225 / Fax: +81-(0)48-462-4715
Email: koho@riken.jp

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

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 >>>