From Science Daily:
The brain still harbours many unknowns. Basically, it is assumed that it stores experiences by altering the connections between brain cells. This ability to adapt — which is also called “plasticity” — provides the basis for memory and learning, which is the ability to draw conclusions from memories. On a molecular scale these changes are mediated by modifications of expression of specific genes that as required strengthen or weaken the connections between the brain cells.
In the current study, a research team led by Dr. Stefan Bonn and Prof. André Fischer from Göttingen, joined forces with colleagues from the DZNE’s Munich site, to examine how the activity of such genes is regulated. The scientists stimulated long-term memory in mice, by training the animals to recognise a specific test environment. Based on tissue samples, the researchers were able to discern to what extent this learning task triggered changes in the activity of the genes in the mice’s brain cells. Their focus was directed on so-called epigenetic modifications. These modifications involve the DNA and DNA associated proteins.
“The cell makes use of various mechanisms in order to turn genes on or off, without altering the DNA sequence itself. It’s called ‘epigenetics’,” explains Dr. Magali Hennion, a staff member of the research group of Stefan Bonn.
In principle, gene regulation can happen through methylation, whereby the backbone of the DNA is chemically labeled at specific sites. Changes in the proteins called histones that are packaging the DNA may also occur.