Neuroscientists have located the cells that store long-lasting memories of traumatic experiences
Using mice engineered to carry a reporter gene signaling neuronal activity, as well as a fear-inducing exercise, researchers were able to identify the subpopulation of neurons that are involved in storing long-term traumatic memories and to locate them in a specific part of the hippocampus: the dentate gyrus.
Next, mice underwent a fear-reducing training resembling exposure-based therapy in humans. Interestingly, mice no longer showed signs of trauma, but the same population of neurons was still active.
Moreover, when researchers reduced the excitability of this population of neurons, mice showed less fear reduction following a similar training--but more when their excitability was enhanced.
Overall, this suggests that the same brain region may be involved in both storing and rewriting traumatic memories.