Yan Zhen/Shanghai Daily news

The plot of the Jim Carrey film "Eternal Sunshine of the Spotless Mind" could one day become true now that researchers at Fudan University have discovered a way to block memories.
Research with mice found that NR2B, a neuron unit in the animal's prefrontal cortex, plays an important role in the establishment, consolidation and retrieval of permanent memories.
The findings could one day be used to wipe out memories of terrible events and treat people with psychological problems, researchers said.
In the movie, Carrey's character had all his memories of a relationship surgically erased after he broke up with his girlfriend.
The team's research has been published in the latest edition of "Neuron," one of the top academic journals in the world, Fudan announced yesterday.
Researchers first put several mice into a box and played a certain piece of music. After a few minutes, they gave the mice an electric shock.
Untreated mice would begin to panic when they were placed back into the box an hour later and the same piece of music was played.
Mice that had their NR2B tissues pharmacologically or genetically blocked didn't react when they were placed back in the box, or when the music began to play, researchers said.
"That's because we successfully deactivated NR2B and destroyed connections between the neurons in which memory codes are stored," said Li Baoming, a professor at Fudan's Institute of Neurobiology.
Without an information source and transmission network, the mice couldn't recall their previous experience, Li explained.
When the mice's memories were blocked by drugs, the effects wore off as the drugs metabolized.
"It'll be a significant breakthrough if we can successfully apply this to medical treatment for human beings, especially those who became too oversensitive after some unforgettable events," he said, adding that pharmacists could target NR2B when researching new medications. Li noted, however, that scientists currently can't distinguish between painful flashbacks and happy memories.