Researchers at the University of Toronto have discovered that specific memories are encoded in just a few cells of the brain, and are hopeful they will be able to switch them off using drugs…

Many more people suffer trauma from painful past events, such as child abuse, road accidents or being the victim of a crime, and can be left with symptoms including flashbacks, bad sleep and paranoid behaviour.

But researchers have shown that they can turn off specific memories in mice and are hoping they will be able to do the same in humans.

Memories are stored in a small network of cells called ‘engrams’ and the University of Toronto discovered that a handful of neurons which become excitable during a fearful event are then recruited to encode the memory by the brain.