How fear burns memories into our brain

Scientists have long known that fear and other highly emotional experiences lead to incredibly strong memoryies. Now, a new research by the neuroscientists at the University of California, Berkeley, has explained how fear burns memories into our brain.

Daniela Kaufer and colleagues reported a new way for emotions to affect memory: The brain's emotional centre, the amygdala, induces the hippocampus, a relay hub for memory, to generate new neurons.

In a fearful situation, these newborn neurons get activated by the amygdala and may provide a "blank slate" to strongly imprint the new fearful memory, she said. In evolutionary terms, it means new neurons are likely helping you to remember the lion that nearly killed you.

"We remember emotional events much more strongly than daily experiences, and for a long time we have known that connections between the amygdala and hippocampus help to encode this emotional information," said Kaufer, an assistant professor of integrative biology and a member of UC Berkeley's Wills Neuroscience Institute.

"Our research shows that amygdala input actually pushes the hippocampus to make new neurons from a unique population of neural stem cells. This provides completely new cells that get activated in response to emotional input."

The finding has implications for post-traumatic stress disorder (PTSD) and other problems caused by faulty regulation of emotional memory.

The study will be published in the journal Molecular Psychiatry.