Something horrible happens. A child is lost. A bomb goes off. A car goes out of control.
And deep in the brain, in the lateral amygdala region, a scattered set of neurons come to life and begin to vibrate with fear.
Through an ingenious set of experiments, a group of researchers at Toronto's Hospital for Sick Children have not only located these terror-laden brain cells in mice, but erased them – along with the frightening memories they stored.
While our imaginations have long been captivated by the idea of altering memory – to sinister effect in George Orwell's 1984 and poignantly in the film Eternal Sunshine of the Spotless Mind – this research suggests a more therapeutic use.
The study, which appears today in the journal Science, may hold out the hope that terrifying memories one day might be erased before they can fester into such conditions as post-traumatic stress disorder.