How the brain stores memories for specific fears

AP Brain cells are shown glowing with multicolor fluorescent proteins. Photo: AP

Neuroscientists are clueing into how the brain is capable of holding and retrieving memories for specific fears, revealing a more sophisticated storage and recall capacity than previously thought.

The study may have implications for treating post-traumatic stress syndrome - as scientists begin to understand how different fears are stored in the brain, they can move toward addressing specific fear memories.

The study was conducted by researchers at New York University (NYU) Centre for Neural Science, NYU department of psychiatry, Copernicus Centre for Interdisciplinary Studies in Krakow, Poland, Emotional Brain Institute at the Nathan S. Kline Institute for Psychiatric Research.

The research focused on the brain's amygdala, which has previously been shown to store fear memories. However, prior studies have indicated that the amygdala does not discriminate among the different threats it holds and processes.

In other words, whether you are afraid of dogs because you were once bitten by a dog or you are afraid of pizza because you once nearly choked to death eating it, all the amygdala remembers is that both of these experiences were scary.

Conversely, other brain areas, such as cortex, ensures that all other aspects of these fearful events in your life are remembered.

The scientists sought to determine if there were differences in how the amygdala processes and remembers fears. To do so, they focused on a process called memory consolidation in which an experience is captured, or encoded, then stored.

Once consolidation occurs, memories may be long lasting - one experience may create memories that last a lifetime. However, whenever recalled, memories become labile - that is, susceptible to changes. This process is called reconsolidation, says a NYU release.

The finding demonstrates that the amygdala makes distinctions among the fear memories it holds and retrieves.