June 28, 2026 | Source: BBC Science Focus | by Hayley Bennett

What is the vagus nerve?

Your brain is connected to your body through a set of 12 crucial nerve networks that descend through your spine and branch out into your body. Of these, the vagus nerve is probably one of the most important. Its tendrils influence digestion, your heart, your reflexes and your breathing.

So you can see why scientists are so interested in what the vagus nerve does – especially when you consider how all of the above affects your mood. You could call it a superhighway between our brains and bodies.

Vagus nerve function

In contrast to the rapid ‘fight or flight’ responses that are under the control of the sympathetic arm of the nervous system, the vagus nerve is responsible for many of the slower, ‘rest and digest responses that we collectively call the parasympathetic arm. The nerve itself is actually two thick bundles of individual neurons (nerve cells) that originate in the brain and pass out to the rest of the body through left- and right-sided openings at the bottom of the skull.