brainscanA brain pathway that underlies the emotional behaviours critical for survival has been discovered, which could provide a breakthrough in developing treatments for panic disorders or phobias, according to researchers.

Researchers from the University of Bristol have identified a chain of neural connections that link central survival circuits to the spinal cord, causing the body to freeze when experiencing fear. 

Understanding how these central neural pathways work is a fundamental step towards developing effective treatments for emotional disorders such as anxiety, panic attacks and phobias. The research is published in the Journal of Physiology.

The periaqueductal grey (PAG) is a brain region responsible for how humans and animals respond to danger and it can trigger responses such as freezing, high heart rate, increase in blood pressure and the desire for flight or fight.

Researchers discovered a brain pathway leading from the PAG to a highly localised part of the cerebellum, called the pyramis. They also found that the pyramis is involved in generating freezing behaviour when central survival networks are activated during innate and learnt threatening situations.

The pyramis may therefore serve as an important point of convergence for different survival networks in order to react to an emotionally challenging situation.

Dr Stella Koutsikou, first author of the study in the School of Physiology and Pharmacology at the University of Bristol, said: “There is a growing consensus that understanding the neural circuits underlying fear behaviour is a fundamental step towards developing effective treatments for behavioural changes associated with emotional disorders.”

Professor Bridget Lumb, professor of systems neuroscience, added: “Our work introduces the novel concept that the cerebellum is a promising target for therapeutic strategies to manage dysregulation of emotional states such as panic disorders and phobias.”

Reference: Koutsikou S, Crook JJ, Earl EV, Leith L, Watson TC, Lumb BM & Apps R (2014) Neural substrates underlying fear-evoked freezing: the periaqueductal grey – cerebellar link. The Journal of Physiology. 

A copy of the paper can be downloaded here