How Fear Returns to the Brain

A team of experts based at the University of Michigan (U-M) argues that a new study carried out on lab rats has finally revealed the neural pathways fear uses to return to the brain, even after having been suppressed through behavioral approaches.

The reason why this study is important is that all behavioral therapies function based on a process called extinction, which involves removing fear from the brain through repeated exposure to low-intensity versions of the stimuli that originally caused the fear.

But this therapy sees fear returning fairly often, due to the activity of the hippocampus, the prefrontal cortex and the amygdala, three critically important regions of the brain. The study found that returning fear activated nerve cells in the hippocampus and PFC that projected to the amygdala.

The latter is the area of the brain that ultimately controls fear. It was additionally discovered that rats in which researchers severed this connection displayed no more fear. This hints at a potential treatment for conditions such as anxiety and post-traumatic stress disorder (PTSD).