Perceiving and reacting to threat is key to survival. A group of brain cells in the brainstem called the periaqueductal gray (PAG) has been regularly hypothesised to be involved in threat perception, although the small size (<5mm3), location and presence of different subdivisions of this structure have make it very difficult to study in humans.
Olivia Faull and colleagues used ultra high-strength MRI scanning to investigate how the human PAG is involved in the perception of the respiratory threat of breathlessness, by scanning subjects' brains whilst making it difficult for them to breathe.
They found that the PAG subdivisions are differentially involved in breathlessness perception, with one PAG subdivision involved in anticipation while another in intensity perception of breathlessness.
Breathlessness causes suffering for millions of people with lung disease, heart disease and cancer. It is often very difficult to treat, and new ways to understand it are needed. This research reveals a new target for understanding how breathlessness and other threat perception may be altered in disease, and potentially how this may be treated in the future.