Old traumatic memories are recalled differently than new ones
People with post-traumatic stress disorder often experience prolonged and exaggerated fearfulness, even when they’re completely out of harm’s way.
The long-term storage of painful or fearful memories is a defence mechanism of sorts. It can help animals (humans included) evade dangerous and potentially life-threatening situations. But in humans, it can also cause severe psychological distress.
Scientists have tried to understand what enables fearful memories to persist with such vigour (and some researchers have even suggested sleep might play a role). Figuring this out could help alleviate the negative psychological effects endured long after traumatic experiences occur.
Now, researchers funded by the US National Institute of Mental Health think they have uncovered an important clue.
In experiments with rats, a team from the University of Puerto Rico discovered that an old fear memory is recalled via a separate brain pathway from the one used to recall the memory when it was still fresh.
The team has published its findings in Nature.
“While our memories feel constant across time, the neural pathways supporting them actually change with time,” explained lead author Gregory Quirk in a press release.
“Uncovering new pathways for old memories could change scientists’ view of post-traumatic stress disorder, in which fearful events occur months or years prior to the onset of symptoms.”
Holding the Bowl 