Navigation Links
Bonn researchers use light to make the heart stumble
Date:10/4/2010

This release is available in German.

Tobias Brgmann and his colleagues from the University of Bonn's Institute of Physiology I used a so-called "channelrhodopsin" for their experiments, which is a type of light sensor. At the same time, it can act as an ion channel in the cell membrane. When stimulated with blue light, this channel opens, and positive ions flow into the cell. This causes a change in the cell membrane's pressure, which stimulates cardiac muscle cells to contract.

"We have genetically modified mice to make them express channelrhodopsin in the heart muscle," explains Professor Dr. Bernd Fleischmann of the Institute for Physiology I. "That allowed us to change the electric potential of the mouse heart at will, enabling us to selectively produce conditions such as arrhythmia of the atrium or the ventricle."

These types of arrhythmia - physicians also call them ventricular fibrillation - are among the most common causes of death after a heart attack. They develop when large quantities of cardiac cells die and are replaced with connective tissue. "This scar tissue has a different electrical activity than the healthy heart muscle," says the leader of the study, Professor Dr. Philipp Sasse. "And that makes the heart stumble."

But why is that so? Normally, electric impulses spread across the heart from a natural pacemaker. This happens in a temporally and spatially tightly controlled manner, creating a closely coordinated contraction. However, if entire muscle areas decouple electrically, this mechanism no longer works: all of a sudden, certain parts of the heart pulse at their own rhythm. This causes the blood flow to come to a near-standstill.

The scientists from Bonn can now trigger this decoupling through photostimulation. They can target just a few cells at a time or direct larger areas of the heart, allowing them to find out, for instance, which areas of the hollow muscle are especially sensitive to electric disruptions.

But why not simply stimulate the heart muscle with electrodes in order to make the heart lose its rhythm? "That can be done as well," says Professor Sasse. " But this method has unwanted side effects: if the electric stimulation lasts longer than a few milliseconds, toxic gases are produced, and the pH value changes."

The consequences of a heart attack, which leads to permanent tissue damage, can of course only be studied in a very limited form when using short-term electric stimulation. Photostimulation is much more suitable: the cells will even withstand stimulations of several minutes at a time without problems.

Using channelrhodopsin in medical research is not fundamentally new, although so far it has mainly been used in neuroscience. For instance, scientists can use these light channels to direct the behavior of flies and mice - with nothing but blue light.


'/>"/>

Contact: Professor Dr. Philipp Sasse
philipp.sasse@uni-bonn.de
49-228-688-5212
University of Bonn
Source:Eurekalert

Related biology news :

1. Researchers engineer adult stem cells that do not age
2. OU researchers selected by Navy
3. Researchers find first genetic evidence for loss of teeth in the common ancestor of baleen whales
4. McLean Hospital researchers awarded $1.9 9 million grant for stem cell, blood research
5. WSU researchers taking sustainability of organic farming to new level
6. Purifying proteins: Rensselaer researchers use NMR to improve drug development
7. Smithsonian researchers find differences between Galapagos and mainland frigatebirds
8. Iowa State, Ames Lab researchers identify structure that allows bacteria to resist drugs
9. Vitamin C rapidly improves emotional state of acutely hospitalized patients, say LDI researchers
10. BUSM researchers to study vitamin D production in fat malabsorption patients
11. Cardiovascular Innovation Institute researchers receive over $2 million grant from NIH
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:7/20/2017)... WASHINGTON , July 20, 2017 Delta (NYSE: ... to board any Delta aircraft at Reagan Washington National Airport (DCA). ... Delta launches biometrics ... Delta,s ... Delta Sky Club is now integrated into the boarding process to ...
(Date:6/23/2017)... ITHACA, N.Y. , June 23, 2017 ... a leader in dairy research, today announced a new ... help reduce the chances that the global milk supply ... this dairy project, Cornell University has become the newest ... Food Supply Chain, a food safety initiative that includes ...
(Date:5/23/2017)... Italy , May 23, 2017  Hunova, the first robotic gym ... trunk, has been officially launched in Genoa, Italy . ... Europe and the USA . The technology ... on the market by the IIT spin-off Movendo Technology thanks to a ... the Multimedia News Release, please click: ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... Oct. 10, 2017 International research firm Parks Associates ... speak at the TMA 2017 Annual Meeting , October 11 in ... the residential home security market and how smart safety and security products ... Parks Associates: Smart ... "The residential security market ...
(Date:10/9/2017)... , Oct. 9, 2017  BioTech Holdings announced ... by which its ProCell stem cell therapy prevents ... ischemia.  The Company, demonstrated that treatment with ProCell ... limbs saved as compared to standard bone marrow ... HGF resulted in reduction of therapeutic effect.  ...
(Date:10/9/2017)... , ... October 09, 2017 ... ... on October 5, 2017, in the medical journal, Epilepsia, Brain Sentinel’s SPEAC® ... gold standard, video EEG, in detecting generalized tonic-clonic seizures (GTCS) using surface ...
(Date:10/6/2017)... ... 06, 2017 , ... The HealthTech Venture Network (HTVN) is ... fourth annual Conference where founders, investors, innovative practitioners and collaborators are invited to ... showcasing early stage digital health and med tech companies. , This day-long event ...
Breaking Biology Technology: