How do we learn? Why do we develop addictions? Is it possible to shut off an epileptic seizure?
Questions like these might now become easier to address: Scientists at the University Medical Center Hamburg-Eppendorf (UKE) and Humboldt University in Berlin have created a novel molecular switch that could be a valuable new tool for brain research.
The new findings of Prof. Thomas Oertner, Prof. Peter Hegemann and their coworkers have just been published in the journal “Science”.
“We inverted the ion selectivity and turned an excitatory channel into an inhibitory one”, explains Prof. Thomas Oertner, director of the Institute for Synaptic Physiology at the Center for Molecular Neurobiology Hamburg (ZMNH). “We were astounded to discover, that a single point mutation – changing a single letter of the genetic code – could be sufficient to completely invert the sign of current flowing through this channel. We also demonstrated that nerve cells can be selectively switched off with our new tool.”
This finding opens up new possibilities for basic research. Thomas Oertner and his team, for example, are planning to use this tool to investigate emotional aspects of learning. It is also conceivable that this channel could be used to dampen the activity of affected brain regions during epileptic seizures.
From algae to brain research – the emerging field of Optogenetics
Channelrhodopsins are proteins that are activated by light, allowing electrically charged ions to pass through biological membranes. Opening these channels changes the voltage across the membrane. In this way, nerve cells can be tuned on or shut off by light. Channelrhodopsins were discovered in unicellular green algae, which use them to swim towards light.
The biophysicist Prof. Peter Hegemann at Humboldt University in Berlin is credited with the discovery of channelrhodopsin, laying the foundation for the new field of optogenetics. With this latest discovery, optogeneticists have a completely new set of tools at their disposal: One of the new proteins, the chloride-conducting channelrhodopsin with slow kinetics or ‘slow ChloC’, opens its pore and shuts off neurons for several seconds after a short flash instead of needing constant light like the older inhibitory tools. “This means, we now need ten thousand times less light to block neuronal activity”, explains Thomas Oertner.
The research project at the UKE was supported by the German Research Foundation (DFG).
Wietek J, Wiegert JS, Adeishvili N, Schneider F, Watanabe H, Tsunoda SP, Vogt A, Elstner M, Oertner TG, Hegemann P (2014). Conversion of Channelrhodopsin into a light-gated chloride channel. Science, March 27, 2014. http://www.sciencexpress.org
Prof. Dr. Thomas G. Oertner
Institute for Synaptic Physiology
Center for Molecular Neurobiology Hamburg (ZMNH)
University Medical Center Hamburg-Eppendorf (UKE)
Phone: +49 (40) 7410-58228
Christine Trowitzsch | idw - Informationsdienst Wissenschaft
Helping to Transport Proteins Inside the Cell
21.11.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
UNH researchers create a more effective hydrogel for healing wounds
21.11.2018 | University of New Hampshire
Innsbruck quantum physicists have constructed a diode for magnetic fields and then tested it in the laboratory. The device, developed by the research groups led by the theorist Oriol Romero-Isart and the experimental physicist Gerhard Kirchmair, could open up a number of new applications.
Electric diodes are essential electronic components that conduct electricity in one direction but prevent conduction in the opposite one. They are found at the...
Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.
Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
19.11.2018 | Event News
09.11.2018 | Event News
06.11.2018 | Event News
22.11.2018 | Physics and Astronomy
22.11.2018 | Agricultural and Forestry Science
21.11.2018 | Life Sciences