A breakthrough from researchers at the University of Technology Sydney has uncovered new information on Thursday, about the mechanism that may be responsible for Post Traumatic Stress Disorder (PTSD).
Results of the study found that animals create a fear memory at rapid speed during a short fear-filled event.
But senior investigator, professor Bryce Vissel, believes another section of the brain - the hippocampus - which is responsible for forming memories of events, places and times at a more gradual speed, “does not have enough time to fully engage.”
“This could be significant because animals rely on their memory of where, when and how the traumatic event occurred to determine when they should be fearful in future,” he said.
“If they form an ambiguous memory that lacks the detail necessary to tell different environments or situations apart, they may trigger the traumatic memory in a variety of inappropriate circumstances.”
“We suggest that this in turn may lead to abnormal fear-related behaviours in irrelevant settings, as is commonly seen in memory disorders such as PTSD.”
To conduct the study, researchers examined the responses of mice when they were exposed to a mild fear inducing experience.
This was able to be measured because it is the natural reaction of mice to freeze when in fear.
“The freezing response required very little exposure time to the fear inducing experience for it to become robust,” Vissel told Xinhua.
“However when we looked in their brains, we found that the animals needed a lot more time to engage the hippocampus.”
This outcome suggests that there could be a disconnect between a fear response and the time it takes to remember the location and circumstances of the fear inducing event.
“We could infer that disorders such as PTSD may not be due to faulty or irrelevant recall of an event in the wrong circumstance, but instead may be due to faulty formation of the original memory, that in turn means that the fear response may be over-generalized and occur in circumstances where it should not,” he said.
“If this idea is true, and I stress if, then it would affect how we may think about treating disorders like PTSD.”