Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


MDC Researchers Gain New Insights into Epilepsy


Just as each musician in an orchestra contributes to the overall sound of a musical piece, different types of nerve cells in the brain make up the symphony of our consciousness.

They regulate and coordinate the activity of groups of neurons that represent parts of information, which they then may transmit to other brain regions. If this precise system is thrown off balance, diseases can develop.

In order to identify the nerve cells in the neuronal network which express the altered glycine receptor researchers inserted an extra gene segment that illuminates the nerve cells (purple). (Photo: Jochen Meier/Copyright: MDC)

Professor Jochen Meier of the Max Delbrück Center (MDC) investigates such processes. Together with his colleagues, he has gained new insights into epilepsy, showing why the disease may present different symptoms (Journal of Clinical Investigation, doi:10.1172/JC171472)*.

The research focus is on the glycine receptor, known from previous studies in the field of spinal cord research as an inhibitory neurotransmitter receptor. Several years ago the research group of neurobiologists showed that this receptor is molecularly altered in patients with intractable temporal lobe epilepsy, one of the most common forms of epilepsy.

Expression of the altered receptor is increased in the hippocampus, a region of the brain that triggers seizures in most patients at later stages of the disease.

Professor Meier, who leads a Helmholtz junior research group at the explained that epilepsy is not exclusively inherited, that is, its cause need not be genetic. In fact, recent research data indicate that various environmental factors, including chronic stress, can cause epileptic seizures.

Resulting molecular and cellular mechanisms may change neuroplasticity to the extent that the affected tissue is no longer able to restore the normal state, which can then lead to chronic epilepsy. This may be one reason why the disease course differs from patient to patient.

The molecular alteration of the glycine receptor in the tissue of epilepsy patients is caused by a process known in research as “RNA editing”. Thereby, in the process of transcription of genetic information from DNA to RNA, individual letters are replaced with others. Enzymes are responsible for the editing of the text.

As a result, the original genetic text encoded in the DNA language no longer corresponds exactly to the RNA, which contains the code for the text building blocks of the proteins. The protein, in this case the glycine receptor, is altered so that it expresses a gain-of-function, and thus functions far more effectively than its non-edited counterpart.

Together with colleagues from Israel and different German universities, Dr. Aline Winkelmann and Professor Meier developed a new animal model of epilepsy to determine the role of this particular glycine receptor variant. This allowed them to express this receptor specifically in selected nerve cell types of the hippocampus and to investigate how it affects cognitive function and mood-related behavior.

They found that the RNA-edited gain-of-function receptor targets the presynaptic terminals, which transfer electrical impulses by releasing a neurotransmitter to other nerve cells. Thus, the function of selected types of nerve cells is strengthened, whereby the whole system of neuronal communication is thrown off balance.

Depending on whether excitatory or inhibitory nerve cells expressed the receptor, the mice were impaired in their cognitive abilities including memory deficits, or they showed increased anxiety.

“Our new animal model suggests that the same molecule can contribute to a wide range of symptoms in epilepsy patients – for example, cognitive dysfunction or anxiety – depending on which type of nerve cell expresses it,” Professor Meier said.

He and his colleagues have thus discovered a disease mechanism which they hope will open up new approaches to the development of targeted treatments for epilepsy patients. He stressed, however, “We must also identify the conductor of this cellular orchestra of dissonant molecular components that is responsible for receptor expression in varied nerve cells in the hippocampus of epilepsy patients.”

*Changes in neural network homeostasis trigger neuropsychiatric symptoms

Aline Winkelmann,1,2 Nicola Maggio,3 Joanna Eller,4 Gürsel Caliskan,5 Marcus Semtner,2 Ute Häussler,6 René Jüttner,7 Tamar Dugladze,4 Birthe Smolinsky,8 Sarah Kowalczyk,8 Ewa Chronowska,9 Günter Schwarz,8 Fritz G. Rathjen,7 Gideon Rechavi,10 Carola A. Haas,6,11 Akos Kulik,9,12 Tengis Gloveli,4,13 Uwe Heinemann,5 and Jochen C. Meier2

1FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany. 2RNA editing and Hyperexcitability Disorders Helmholtz Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany. 3Talpiot Medical Leadership Program, Department of Neurology and the J. Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel HaShomer, Israel. 4Cellular and Network Physiology Group, Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany. 5CC2 Zentrum für Physiologie, Freie Universität Berlin, Berlin, Germany. 6Experimental Epilepsy Research, Department of Neurosurgery, Neurocenter, University of Freiburg, Freiburg, Germany. 7Developmental Neurobiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany. 8Institute of Biochemistry, University of Cologne and Center for Molecular Medicine, Cologne, Germany. 9Department of Physiology II, University of Freiburg, Freiburg, Germany. 10Sheba Cancer Research Center, The Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. 11BrainLinks-BrainTools, Cluster of Excellence and 12BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany. 13Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany.

Barbara Bachtler
Press Department
Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch
in the Helmholtz Association
Robert-Rössle-Straße 10
13125 Berlin
Phone: +49 (0) 30 94 06 - 38 96
Fax: +49 (0) 30 94 06 - 38 33

Weitere Informationen:

Barbara Bachtler | Max-Delbrück-Centrum

Further reports about: Epilepsy Helmholtz MDC Max-Delbrück-Centrum Molecular RNA cognitive glycine receptor

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>