How does vagus nerve stimulation work?

Vagus nerve stimulation (VNS) involves activating the vagus nerve through different methods, impacting various physiological processes. One common method uses an implanted electrical stimulation device attached to a branch of the vagus nerve that does not affect breathing or swallowing. This precise stimulation targets specific neural pathways and can affect mood and alertness by activating deep brain centers and altering neurotransmitter release, such as dopamine 1.

The vagus nerve also interfaces with neurons in the gut, part of the gut-brain axis. These neurons respond to the presence of sugars, fatty acids, and amino acids, sending signals via the vagus nerve to the brain. This process can induce dopamine release from deep brain centers, influencing our cravings and eating behaviors without the influence of taste 1.

Moreover, VNS can balance the sympathetic and parasympathetic nervous systems. By enhancing the parasympathetic response (rest-and-digest), VNS can reduce overactivity in the sympathetic system (fight-or-flight), potentially helping with conditions like irritable bowel syndrome or arthritis by reducing inflammation and stress states 2.

The vagus nerve's influences are extensive, impacting digestion, heart rate, and even our mental state through its complex network connecting the brain to various organs and through bi-directional communication 3.