The findings, which appear in the current issue of the journal Science, provide new insights into nerve cell communication in the brain that could also play a role in stroke.
Nerve cells of both hemispheres in the brain have to communicate with each other so that the body can perform certain functions. Photo: Philipp Mergenthaler
On the way to the brain, nerve pathways in the human body cross each other. As a result, stimuli are processed in the opposite hemisphere of the brain. For example, if someone touches our right hand, the stimulus is received in the left half of the brain.
However, both halves of the brain have to coordinate their activities. Since some functions, such as language, are strongly pronounced in only one half of the brain, their signals always have to be communicated to the other half. This is even more obvious in daily activities such coordinating the hands or feet, which requires very precise communication between both brain hemispheres. The signals that reach the brain hemispheres are sent via a massive nerve pathway called the corpus callosum from one half of the cerebral cortex to the other.
The research group of Matthew Larkum of the Cluster of Excellence NeuroCure at the Charité – Universitätsmedizin Berlin and Humboldt-Universität zu Berlin investigates the mechanisms in the brain controlling neuron activity in the cerebral cortex. In their current study in cooperation with the University of Bern, the researchers focused on the processing of tactile sensations. To do this Larkum and his team used a range of methods such as intracellular measurements of single nerve cells in the intact brain and various imaging techniques during the sensory stimulation of the hind paw of a rat.
The scientists discovered that stimulating the right and left paws of the rat has a relatively slow, nearly half-second-long sustained inhibitory effect on nerve cell activity. „That is very slow“, notes Larkum. „Normally, signal transmission happens much faster. For that reason, we wanted to find out which circuit of nerves underlies this mechanism and identify the cellular communication pathways,“ he further explains.
The researchers were able to do this with the help of a new technology called optogenetics, which makes it possible to stimulate specific nerves with light. The researchers could show that nerve fibers coming out of the opposite hemisphere activate a special group of local inhibitory nerve cells. These nerve cells in turn activate slow-acting receptors that lead to lower activity in the other nerve cells of the same brain hemisphere.
For stroke research in particular, these findings could be an additional building block in the development of new therapies, as this mechanism plays an important role in the disease. However, communication between the brain hemispheres in the cerebral cortex is crucial not only in stroke damage but also for a range of cognitive abilities, which is why the results of this study could have far-reaching impact.
NeuroCure is a Cluster of Excellence at the Charité – Universitätsmedizin Berlin funded as part of the Excellence Initiative of the German federal and state governments. The focus of this interdisciplinary research alliance is on translating results from basic neuroscience research into clinical application. A better understanding of underlying disease mechanisms contributes to developing effective treatments for neurological diseases such as stroke, multiple sclerosis and epilepsy.
In addition to the Charité, NeuroCure partners include the Humboldt-Universität zu Berlin, Freie Universität Berlin, Max Delbrück Center for Molecular Medicine (MDC), Leibniz Institute for Molecular Pharmacology (FMP) and Deutsches Rheuma-Forschungszentrum (DRFZ).
Palmer LM, Schulz JM, Murphy SC, Ledergerber D, Murayama M, Larkum ME (2012) The cellular basis of GABAB-mediated interhemispheric inhibition. Science In press.Kontakt:
Constanze Haase | idw
Navigational view of the brain thanks to powerful X-rays
18.10.2017 | Georgia Institute of Technology
Separating methane and CO2 will become more efficient
18.10.2017 | KU Leuven
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...
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....
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...
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...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
18.10.2017 | Physics and Astronomy
18.10.2017 | Physics and Astronomy
18.10.2017 | Life Sciences