Washington: In a development that could help
in the treatment of post-traumatic stress syndrome, a new
study has found that the brain is capable of holding and
retrieving memories for specific fears.
A research led by scientists at New York University`s
Center for Neural Science showed that the brain has a more
sophisticated storage and recall capacity than previously
thought.
The study, published in the journal Nature Neuroscience,
will help understand how different fears are stored in the
brain and the health experts can now move towards addressing
specific fear memories.
The team 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. By contrast, other brain areas like cortex ensures that
all other aspects of fearful events are remembered.
The new study sought to determine if there were
differences in how the amygdala processes and remembers fears.
For that, the researchers focused on a process called
memory consolidation in which an experience is captured, or
encoded, then stored.
According to earlier researches, once consolidation
occurs, memories may be long lasting -- one experience may
create memories that last a lifetime but whenever recalled,
memories become labile -- that is, susceptible to changes
which is called reconsolidation.
However, the new study yielded quite different results.
The team found that re-exposing a rat to a particular shock,
followed by an injection of an antibiotic known to disrupt
reconsolidation processes, impaired only these associations
that were linked to this particular shock.
Despite the disruption of one type of fear memory, rats
were still able to express fear behaviour same as the other
group which had been paired with a shock applied to another
part of the body.
The finding demonstrates that the amygdala makes
distinctions among the fear memories it holds and retrieves.
PTI
