London, Nov 3 (IANS) A new technique promises to delete painful memories permanently, possibly opening the way for more effective treatment of post-traumatic stress disorder, scientists say.

A team at Johns Hopkins University in the US conducted tests on mice and removed a protein from the region of the brain responsible for recalling fear.

The mice were then unable to recall the fear they experienced when a loud sound was played prior to the experiment, according to the journal Science Express.

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, reports the Daily Mail.

Lead researcher 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," he said.

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 relapses common.

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

Experimenting on mice, they observed that certain cells in the amygdala region conducted more current after the mice were 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, scientists said.