It’s one of the most basic emotions. Something everyone has felt before. However, its mechanisms are not fully defined. How does fear arise in the brain? Some University of California researchers believe they have the answer. They used a mouse model.
It’s all in your head
The hippocampus is involved, reacts to a particular context, and codes it. And the amygdala, which triggers defensive behavior. Including the scary answers. The results are in the magazine Nature communication.
“There was a hypothesis that linked the hippocampus and the amygdala,” explains Jun-Hyeong Cho. He is a professor at the University of California and lead author of the study. “However, the experimental evidence had been weak. Our study proves this for the first time. The memory of fear is associated with a context. And it strengthens the connections between the hippocampus and the amygdala.
Weakening these connections could erase the memory of the fear. “They would help in therapeutic strategies to suppress fear memories. It would be useful in patients with post-traumatic stress disorder, ”he adds. Post Traumatic Stress Disorder, or PTSD, affects 7% of the US population. It can cause problems in daily life for months and even years.
Our brain forms a memory of fear associated with a situation that predicts danger. It enables us to avoid these dangerous situations in the future. However, this process is unregulated in PTSD. The reactions to fear are exaggerated. This includes nightmares or unwanted memories of the trauma. Also anxiety and a depressed mood.
“The neurological mechanism of learned fear has enormous survival value. Suppose we were in a car accident in a certain location. We might be scared of this place long after we have recovered. Our brain connects the accident with the experienced situation. We would tend to avoid situations that are equally threatening to us.
This memory is linked to the traumatic event. Knowing how fear arises in the brain is only the first step. New strategies can now be explored to suppress memories of pathological anxiety.