Deeply traumatic events can affect us at a cellular level, literally. Traumas are fear-based memories that embed themselves into our brains with neuron activity. Recent research may provide a clue as to where exactly the brain stores trauma by examining neurons and how these neurons can be activated to rewrite trauma.
Once traumas are in our emotional memory, they can alter our sense of being and our behavior. Treating them is a task onto itself but neuroscientists may have uncovered a new way to release the brain from the confines of trauma.
It involves a therapy that “rewrites” memories and comes from a study published in the journal Science. Results show that the process may be successful with treating even long-term traumas.
The study comes from researchers from the École Polytechnique Féderale de Lausanne in Switzerland. They found that weakening traumatic memory in the brain involves the same neurons that also work with storing the traumatic memories.
Using genetically engineered mice that carried a “reporter” gene—that’s a gene that produced a fluorescent protein that tracked neuronal activity—they located these neurons in the hippocampus (inside the dentate gyrus). The hippocampus is part of the brain’s limbic system and processes memory. It’s where the encoding, recall and reduction of fear take place. The limbic system is like a machine that helps us recognize events, people and where traumas preside.
The scientists used a fear-training exercise that produced long-lasting traumatic memories in the mice. The team identified where those memories were exactly stored.
The mice then underwent a type of exercise that resembles exposure-based therapy in humans. The American Psychological Association recommends exposure therapy as one of the cognitive behavioral therapies for fear attenuation. The therapy involves creating a safe environment in which patients are exposed to traumas in order to reduce the fear associated with the trauma and decrease avoidance. It works for individuals with Post Traumatic Stress Disorder (PTSD), anxiety, phobias and other conditions.
After researchers exposed the mice to such therapy they found some of the neurons that had been active with recalling the trauma were still active when the mice no longer showed fear. The less fear the mice showed, the more cells became reactivated. When the researchers manipulated the recall neurons by stimulating them during exposure therapy the mice demonstrated less ability to reduce fear compared to a control group.
Study results demonstrate that the recall neurons in the dentate gyrus are crucial for weakening fear and once that happens it can improve fear attenuation. Conclusions drawn from the study also mean that it’s possible that to weaken fear-based memories depending on the activity of the recall neurons. Hypothetically, researchers could manipulate the neurons to “rewrite” traumas.
Results from the study also pose the question as to whether it’s best to suppress the original memory of a trauma with a new memory associated with safety (as in EBT); or, if rewriting trauma memory, like in the experiment, leads the fear toward a strong safety association?
While research in trauma reduction has focused on the understanding of the brain’s capacity to reduce traumatic memories, neuroscientists still have to research more on how neurons store memories in general.