Navigation Links
A brain filter for clear information transmission
Date:9/6/2012

This press release is available in German.

Stefan Remy and colleagues at the German Center for Neurodegenerative Diseases (DZNE) and the University of Bonn have illuminated how this system works. "The system acts like a filter, only letting the most important impulses pass," explains Remy. "This produces the targeted neuronal patterns that are indispensible for long-term memory storage."

How does this refined control system work? How can inhibitory signals produce precise output signals? This was the question investigated by Remy and his colleagues. Scientists have known for some time that this inhibitory system is crucial for the learning process. For instance, newest research has shown that this system breaks down in Alzheimer's patients. Remy and his team investigated the nerve cells of the hippocampus, a region of the brain that plays a crucial role in memory formation.

The information we learn or remember is processed in the brain through nerve impulses. Incoming signals enter the cell as excitatory signals. Here, they are processed via branched structures, known as dendrites, and are sent selectively to neighboring neurons. The dendrites in this brain region serve as efficient amplifiers for synchronous signals.

"We were able to show that in specific dendrites, the 'strong' dendrites, clustered signals are amplified very well. 'Weak' dendrites only transmit signals in certain phases," says Christina Mller, postdoctoral student in Remy's working group and the lead author of the study to appear in Neuron. Dendrites are excitable to differing degrees. 'Strong' dendrites transmit synchronous excitatory signals precisely and very reliably. They can resist any inhibition. Thus ensures specific signals, perhaps most relevant for learning and memory, are reliably transmitted. This results in defined patterns of activity that are repeated regularly, creating simultaneous excitation and a combination of specific cell groups (assemblies).

"It is assumed that this coactivation of cell assemblies is a cellular correlate for learning," says Mller. If associations are to be stored in long-term memory, certain neuronal groups must be precisely and repeatedly activated in the same order. These activity patterns are enabled by the inhibitory system. It explains why the absence of this system in Alzheimer's patients has such dramatic consequences. Without it, the storage of associations in long-term memory cannot take place.

Signals that are received via 'weak' dendrites can only be passed forward during phases of weak inhibition. They can however be transformed into 'strong' dendrites during this process. According to Remy and his colleagues, only then can these dendrites provide precise signal transmission. Scientists call this "intrinsic plasticity". "This makes sense. Because this is how neuronal networks can be coupled with each other and the coupling made permanent," explains Remy. "This is a totally new learning mechanism. Here the change does not take place at the synapse where it's already been observed but at the dendrite." This mechanism mostly takes place during phases of heightened activity, such as when we experience something new.

The findings of Remy and his colleagues represent an important step toward better understanding the mechanisms of learning and memory.


'/>"/>
Contact: Sonja Jlich-Abbas
sonja.juelich-abbas@dzne.de
49-228-433-02263
Helmholtz Association of German Research Centres
Source:Eurekalert

Related biology news :

1. REST is crucial for the timing of brain development
2. Holding a mirror to brain changes in autism
3. Strong scientific evidence that eating berries benefits the brain
4. The Japanese traditional therapy, honokiol, blocks key protein in inflammatory brain damage
5. Step forward in research into new treatments for brain edema
6. University of Alberta led research may have discovered how memories are encoded in our brains
7. Nanotherapy: Treating deadly brain tumors by delivering big radiation with tiny tools
8. Friendly to a fault, yet tense: Personality traits traced in brain
9. New discoveries about brain-hand connection sought to improve therapies, treatments, prosthetics
10. Autism risk gene linked to differences in brain structure
11. Amyloid beta in the brain of individuals with Alzheimers disease
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/5/2017)... 2017  The Allen Institute for Cell Science today ... one-of-a-kind portal and dynamic digital window into the human ... first application of deep learning to create predictive models ... and a growing suite of powerful tools. The Allen ... future publicly available resources created and shared by the ...
(Date:3/30/2017)... , March 30, 2017  On April 6-7, ... Hack the Genome hackathon at Microsoft,s headquarters ... two-day competition will focus on developing health and wellness ... Hack the Genome is the first ... tremendous. The world,s largest companies in the genomics, tech ...
(Date:3/27/2017)... , March 27, 2017  Catholic Health ... and Management Systems Society (HIMSS) Analytics for achieving ... Adoption Model sm . In addition, CHS previously ... U.S. hospitals using an electronic medical record (EMR). ... its high level of EMR usage in an ...
Breaking Biology News(10 mins):
(Date:4/27/2017)... ... ... Mitotech S.A, a Luxembourg based clinical stage biotechnology company, announced positive results of ... devastating genetic disease that leads to a sudden and rapid loss of central vision. ... 11778, 14484 and 3460 mutations and having experienced the onset of symptoms more than ...
(Date:4/27/2017)... ... April 27, 2017 , ... ... rebrand and a name change to Fluence Analytics. , Fluence Analytics ... of polymer and biopharmaceutical manufacturing processes and R&D applications. The company’s patented ...
(Date:4/26/2017)... ... April 26, 2017 , ... Looking ... team-building and cooking events company, offers one-of-a-kind gifts, ranging from gourmet cooking experiences ... California cuisine, and guests leave inspired with new cooking tips and techniques, thanks ...
(Date:4/26/2017)... ... April 26, 2017 , ... NextSteps 2017, NetDimensions’ annual global ... this May on the following dates: , ?    London, UK from May 10-11, ... Learning and Performance Institute will be the opening keynote speaker at the ...
Breaking Biology Technology: