Researchers have now successfully tracked down the molecular bases of these strong, persistent memories.
It has long been known that emotional memories of both a positive and a negative kind make strong impressions on your brain, and consequently have a very large effect on your behavior.
A research group has shown that the enzyme calcineurin and the gene regulation factor Zif268 decisively determine the intensity of emotional memories. For the first time, this has enabled the regulatory processes at the synapse, which are important for emotional memories, to be linked to the processes in the cell nucleus.
Researchers found that although traumatic memories can be overcome slowly through intensive training, they are not replaced. Negative memories, they say, need to be actively replaced by positive memories.
While the research has no clinical applications at present, it could eventually lead to an understanding of the mechanisms underlying psychological traumas or brain diseases related to memory problems.