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
|Contact: Sonja Jlich-Abbas|
Helmholtz Association of German Research Centres