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
Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University
How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy