Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Epilepsy: Signals ’Brake’ in Brain Impaired


To date epilepsy research has mainly concentrated on the transmission of the nerve cell signals to what are known as the synapses. However, recent observations by medical researchers from the US, France and the University of Bonn support the idea that in ’falling sickness’ the signal processing in the nerve cells (neurons) is altered: normally specific ion channels absorb the neuronal activity. In rats suffering from epilepsy, however, this signals brake seems impaired: they have far fewer functioning ion channels than healthy rats. The results are published in the latest edition of the prestigious scientific journal ’Science’ (23rd July, vol. 305, no. 5683). They offer hope of new therapeutic possibilities.

Epilepsy is a common disease: in Germany alone there are 600,000 people whose nerve cells in the brain occasionally switch from healthy chaos to common mode. The result of the uncontrolled mass discharge of neurons is loss of consciousness and spastic convulsions of the muscles, during which those affected can seriously injure themselves. Yet how this synchronised paroxysmic activity develops at the level of nerve cells is still largely a mystery.

Nerve cells are interlinked via a large number of branching networks through which they communicate with each other. Each neuron has a series of dendrites which receive signals from other neurons at what are known as synapses. The cell ’processes’ these incoming signals like a kind of biological microprocessor and transmits as a result electrical pulses via a special projection, the axon, to the dendrites of other neurons. Many epilepsy researchers have up to now assumed that when epilepsy occurs this communication between the cells does not work properly because the transmission of the signals to the synapses is impaired. However, the Bonn researchers in conjunction with their US colleagues and a research team from Marseilles discovered in the case of epileptic rats that the signal processing is not only affected in the synapses but also in the neurons themselves.

The nerve cells are surrounded by a cell membrane. Yet this membrane is not impervious: different kinds of specialised pores ensure that specific charged particles, the ions, can pass through the membrane. Some of these ion channels are permanently open, others only let ’their’ ions through when needed or use energy to ’pump’ them against a concentration gradient. One important ion pore is the Kv4.2 channel, which is permeable for positively charged potassium ions. This channel is mainly located at the signal inputs of a neutron, the dendrites, and has an important function there: it absorbs incoming excitant signals from other nerve cells. They ’trickle away’, so to speak, through the many little ’potassium leaks’; on their journey through the dendrites the pulses therefore level out more and more.

’In rats with what we call a temporal lobe epilepsy some dendrites have far fewer functioning Kv4.2 channels than healthy rats,’ the Bonn epilepsy researcher Professor Heinz Beck explains. There are two reasons for this, the researchers were able to show: on the one hand the genes for the potassium sluice are read less often, with the result that the cells produce fewer Kv4.2 channels. On the other hand a particular enzyme, the ERK or Extra-Cellular Signal-Regulated Kinase, changes the channels present chemically in such a way that they no longer function. The consequence is, Professor Beck adds, that ’since the input signals at the dendrites reach the neuron largely unabsorbed, the rats probably react much more frequently than healthy rats by transmitting an impulse to their signal output, the axon.’ The nerve impulses can therefore multiply more easily; the lack of signal absorbance may thus decisively contribute to the increased excitability of the neurons in chronic epilepsy.

When the teams impeded the ERK with specific substances, the signal response of the nerve cells largely normalised. The findings therefore make it appear possible to discover new therapeutic approaches. ’Admittedly, the ERK has so many tasks to do that there would probably be side-effects if it was impeded directly,’ says Heinz Beck. ’However, the attempt could be made to protect the Kv4.2 channels from ERK attack, or reverse the chemical changes in the channels.’

Professor Heinz Beck | alfa
Further information:

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

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...

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

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>