Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists shed new light on walking

22.01.2010
Researchers at the medical university Karolinska Institutet have created a genetically modified mouse in which certain neurons can be activated by blue light.

Shining blue light on brainstems or spinal cords isolated from these mice produces walking-like motor activity. The findings, which are published in the scientific journal Nature Neuroscience, are of potential significance to the recovery of walking after spinal cord injury.

"This new mouse model will impact the way in which future studies examining the organization of neurons involved in walking are performed. We hope that our findings can provide insight that eventually will contribute to treatments for spinal cord injured patients"", says Professor Ole Kiehn, who lead the study.

Excitatory neurons have been suggested to play an important role for the initiation and maintenance of locomotion, or walking. However, this has not been demonstrated directly. In order to test the hypothesis that activation of excitatory neurons is essential to locomotion, a research team at the Department of Neuroscience, Karolinska Institutet, created a genetically modified mouse which expresses a light sensitive protein in excitatory neurons.

The light sensitive protein, Channelrhodopsin2 (ChR2), is normally found in algae and activates the cell it is expressed in when exposed to blue light. ChR2 has previously been introduced into rodent cells by viral infection, but this can be problematic due to exposure and replication demands. The researchers circumvented the problems by creating the first genetically modified mouse to successfully express ChR2 in a specific set of neurons.

By inserting ChR2 into nerve cells expressing Vglut2 - a transporter found in most excitatory neurons in the brainstem and spinal cord as well as many excitatory neurons in other regions of the brain - they created a Vglut2-ChR2 mouse . The reason for doing this was to be able to selectively activate excitatory neurons in specific regions of the brainstem and spinal cord, as the excitatory neurons are believed to be important for initiating locomotion, or walking.

The researchers then recorded from motor nerves leaving the spinal cord. When blue light was shined directly on the spinal cord, walking-like activity began and was maintained for the duration of the light pulse. This proved that activation of Vglut2-expressing excitatory neurons in the spinal cord is sufficient for walking. Walking-like activity could also be initiated by exposing the lower brainstem to blue light, demonstrating that excitatory cells in the brainstem provide a sufficient 'go' signal to the spinal neurons involved in walking.

All the experiments were made in vitro in the laboratory and not in living animals.

Publication
Martin Hägglund, Lotta Borgius, Kimberly J Dougherty & Ole Kiehn
Activation of groups of excitatory neurons in the mammalian spinal cord or hindbrain evokes locomotion

2010, doi:10.1038/nn.2482. Print issue 25 January 2010

For more information, please contact:
Professor
Ole Kiehn
Department of Neuroscience
Work: +46 8 524 839 51
Mobile: +46 70 6857821 E-mail: O.Kiehn@ki.se
Press Officer
Katarina Sternudd
Work: +46 8 524 838 95 E-mail: katarina.sternudd@ki.se

Katarina Sternudd | EurekAlert!
Further information:
http://www.ki.se

More articles from Health and Medicine:

nachricht The end of pneumonia? New vaccine offers hope
23.10.2017 | University at Buffalo

nachricht Scientists track ovarian cancers to site of origin: Fallopian tubes
23.10.2017 | Johns Hopkins Medicine

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>