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
Colorectal cancer risk factors decrypted
13.07.2018 | Max-Planck-Institut für Stoffwechselforschung
Algae Have Land Genes
13.07.2018 | Julius-Maximilians-Universität Würzburg
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
13.07.2018 | Event News
13.07.2018 | Materials Sciences
13.07.2018 | Life Sciences