Eternal sunshine? Scientists create technique to delete traumatic memories



Researchers have found a way of permanently deleting painful memories, which they say could lead to drugs for post-traumatic stress disorder.

A team at John Hopkins University in the U.S removed a protein from the region of the brain responsible for recalling fear in tests on mice.

The mice were then unable to recall fear associated with a loud sound.

Science-fiction could soon be reality after researchers found a way to delete painful memories. The concept was explored in the film Eternal Sunshine Of A Spotless Mind where Jim Carrey (pictured) and Kate Winslet decide to erase each other from their memories after a difficult break-up

The method is similar to that imagined in the film Eternal Sunshine Of The Spotless Mind, where Jim Carrey and Kate Winslet decide to erase each other from their memories after a difficult break-up.



The scientists, whose report appears in Science Express, said it had important implications for patients whose lives were blighted by fear.

Lead researcher, Dr Richard L Huganir, said: 'When a traumatic event occurs, it creates a fearful memory that can last a lifetime and have a debilitating effect on a person’s life.

'Our finding describing these molecular and cellular mechanisms involved in that process raises the possibility of manipulating those mechanisms with drugs to enhance behavioural therapy for such conditions as post-traumatic stress disorder.'



Behavioural therapy has been shown to ease the depth of the emotional response to traumatic memories, but not in completely removing the memory itself, making relapse common.



Dr Huganir and post-doctoral fellow Roger Clem focused on the nerve circuits in the amygdala, the part of the brain known to underly so-called fear conditioning in people and animals.



Using sound to cue fear in mice, they observed that certain cells in the amygdala conducted more current after the mouse was exposed to a loud, sudden tone.



They found temporary increases in the amount of particular proteins - the calcium-permeable AMPARs - within a few hours of fear conditioning that peaked at 24 hours and disappeared 48 hours later.

These particular proteins are uniquely unstable and can be removed from nerve cells.



Dr Huganir said: 'The idea was to remove these proteins and weaken the connections in the brain created by the trauma, thereby erasing the memory itself.'

In further experiments, they found that removal of these proteins depended on the chemical modification of the GluA1 protein.

Mice lacking this chemical modification of GluA1 recovered fear memories induced by loud tones, whereas litter mates did not recover the same fear memories.



Dr Huganir suggests that drugs designed to control and enhance the removal of calcium-permeable AMPARs may be used to improve memory erasure.

Dr Huganir said: 'This may sound like science fiction, the ability to selectively erase memories.

'But this may one day be applicable for the treatment of debilitating fearful memories in people, such as post-traumatic stress syndrome associated with war, rape or other traumatic events.'

This study was funded by the National Institutes of Health and the Howard Hughes Medical Institute.