Memories linger in a person's mind for a long time, which can be debilitating when the memory is particularly traumatic.
Now, scientists say that the brain can be stimulated to enhance positive emotions associated with memories and suppress negative ones, which could potentially make traumatic memories less powerful.
These findings, published in the journal Current Biology, could be used in the future to develop effective treatments for people suffering from PTSD, depression, and anxiety, among other conditions.
The hippocampus stores all the information making up a person's memories, whether they're good or bad. This cashew-shaped region of the brain contains many subregions, which all work together to create the different elements of each specific memory.
"Many psychiatric disorders, especially PTSD, are based on the idea that after there's a really traumatic experience, the person isn't able to move on because they recall their fear over and over again," explained study author Briana Chen of Columbia University in a news release.
In the new study, researchers suggested that these memories can actually be manipulated if they know the regions of the hippocampus to stimulate.
To reach their conclusions, the researchers used optogenetics to identify the hippocampus cells becoming activated when male mice are making positive, negative, or neutral memories. By finding the cells involved in the memory-making process, they can stimulate these same cells to either suppress or enhance the feelings linked to the memories.
Findings showed that the top and bottom parts of the hippocampus appear to play different roles in memories. Stimulating the memory cells at the bottom of the hippocampus can cause fear and anxiety-related behavioral changes, while the ones at the top of the hippocampus seem to function like exposure therapy as it reduces the emotional trauma of bad memories and makes them more bearable to recall.
Potential For Future Treatments
Study author Steve Ramirez from Boston University explained that their research suggests that the bottom part of the hippocampus could be overactive when memories become too emotionally loaded and debilitating. Treatments for conditions related to memories such as PTSD could eventually be developed by suppressing overactivity in this part of the brain.
Looking even further ahead, Ramirez said that this part of the brain could eventually be used to enhance cognitive skills in the same way pills are used to improve memory and brain function in the film Limitless.
"It sounds like sci-fi but this study is a sneak preview of what's to come in terms of our abilities to artificially enhance or suppress memories," pointed out Ramirez.