Researchers from MIT's Picower Institute for Learning and Memory have uncovered a molecular mechanism that governs the formation of fears stemming from traumatic events. The work could lead to the first drug to treat the millions of adults who suffer from debilitating fears, including hundreds of soldiers with post-traumatic stress disorder (PTSD) who are returning from service in Iraq and Afghanistan.
The researchers showed that inhibiting a kinase (enzymes that change proteins) called Cdk5 facilitates the extinction of fear learned in a particular context. Conversely, the learned fear persisted when the kinase's activity was increased in the hippocampus, the brain's center for storing memories.
Emotional disorders such as post-traumatic stress and panic attacks stem from the inability of the brain to stop experiencing the fear associated with a specific incident or series of incidents. For some people, upsetting memories of traumatic events do not go away on their own, or may even get worse over time. The researchers found that some of the molecular machinery that initially encodes the troubling memories also regulates their extinction.