Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mechanism for memory revealed in neurons of electric fish

20.02.2006


Researchers from The University of Texas at Austin studying electric fish have gained new insight into how memory is stored at the level of neurons.



Their finding, published in the Feb. 16 issue of Neuron, could help researchers better understand memory formation and neural disorders like epilepsy in humans.

Dr. Harold Zakon, Dr. Jörg Oestreich and colleagues show that when electric fish zap each other in dark waters, their neurons store a memory of the sizzling communiqué by turning on special cell membrane channels.


The channels give the fish neurons the ability to retain a memory long after its original stimulus is gone.

"There is short-term stimulation that results in long-term changes in excitability," says Zakon, professor of neurobiology. "Essentially, it is memory."

The electric fish studied by Zakon and Oestreich discharge electrical signals to survey their environment and communicate with each other.

"Every time they discharge, it’s kind of like they are opening their eyes and closing them," says Zakon. "Each pulse of electricity is a snapshot of the environment. These guys are swimming around and discharging at a very regular frequency. They’re digitizing their environment."

But a problem occurs when the fish are close to each other. They can jam each other’s electrical signals. In response, one of the fish will jump to a higher frequency to avoid the jamming signal, emitting more electrical pulses per second than its neighbor.

Oestreich and Zakon found that once the jamming avoidance has started, the fish’s neurons continue to discharge at a higher frequency, even after its neighbor fish may have swum away.

The researchers discovered that the neurons’ memory was not caused by increased flow of glutamate to their synapses. Glutamate is the major excitatory neurotransmitter in the nervous system and is involved in the processes of learning and memory. They blocked glutamate and found that it did not affect the memory of the neurons.

Instead, the glutamate sets off a cascade of events in the neuron that results in the activation of ion channels, called TRP channels, which then remain active for a long time.

"The long-term activation of these TRP channels," says Zakon, "is the ’memory.’"

Zakon, Oestreich and colleagues don’t yet understand how the stimulus leads to the long-lasting activation of the TRP channel. They are pursuing further studies.

"We’re looking at the general idea that we have long-term changes in the brain that affect the computation that neurons do," says Zakon. "We have ion channels [in the neurons] and we know those are activated. The mystery is how a short stimulus leads to such a long-lasting activation of the TRP receptor."

Harold Zakon | EurekAlert!
Further information:
http://www.utexas.edu

More articles from Life Sciences:

nachricht Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides
16.07.2018 | Tokyo Institute of Technology

nachricht The secret sulfate code that lets the bad Tau in
16.07.2018 | American Society for Biochemistry and Molecular Biology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

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...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

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...

Im Focus: Breaking the bond: To take part or not?

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...

Im Focus: New 2D Spectroscopy Methods

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....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>