Polyvagal Theory - The Dorsal Vagal Complex

The Dorsal Vagal Complex

The dorsal branch of the vagus originates in the dorsal motor nucleus and is considered the phylogenetically older branch. This branch is unmyelinated and exists in most vertebrates. This branch is also known as the “vegetative vagus” because it is associated with primal survival strategies of primitive vertebrates, reptiles, and amphibians. Under great stress, these animals freeze when threatened, conserving their metabolic resources.

The DVC provides primary control of subdiaphragmatic visceral organs, such as the digestive tract. Under normal conditions, the DVC maintains regulation of these digestive processes. However, prolonged disinhibition can be lethal for mammals, as it results in apnea and bradycardia.