Last updated February 22, 2018 at 9:43 am
Researchers have discovered a new pathway in the brain that regulates the return of traumatic memories and fear.
Dr Roger Marek and Professor Pankaj Sah from the Queensland Brain Institute say their finding has potential implications for treating trauma-related disorders, including post-traumatic stress disorder (PTSD).
“A common approach of cognitive-behavioural therapies to treat patients with trauma-related disorders such as PTSD is often done using exposure therapy, which is based on an experimental paradigm known as ‘extinction learning’,” says Dr Marek.
“This procedure aims to uncouple a stimulus from triggering a response – in this case, fear.”
“Despite the success of these treatments in providing therapeutic relief to patients, extinction training does not totally erase traumatic memories, but rather suppresses its expression. Previous research in both rats and humans has found that the fear ‘relapses’ under certain circumstances.
“We know that extinction memories are context dependent. For example, in people undergoing exposure therapy, extinction learning takes place within a clinical setting and has been found to lead to a relapse of the fear outside of the clinic.
“In our latest study, we found that abnormal neural communication between the hippocampus, a brain region crucial for memory storage, and a prefrontal structure known as the infralimbic cortex causes fear relapse.
“For this reason, understanding the neural circuits underlying the relapse of extinguished fear is critical so we can develop more effective therapies for conditions including PTSD.”
The study was conducted with researchers from the Texas A&M University.
The paper published in Nature Neuroscience.