The researchers suspected that such effects were controlled by signals from the gut that are being transmitted by the vagus nerve, which connects gut and brain.
The brain uses the vagus nerve to connect and communicate with many parts of the body, including the vocal cords, heart, lungs and most of the digestive tract.
First, the vagus nerve, which runs through the body into the brain, quickly transmits the information to the brain stem, passing near an important area of pain processing.
Beyond their evidence that the vagus nerve is crucial to the relationship, for example, Dr Bravo and his colleagues do not yet know the precise mechanisms at work.
It had punctured the carotid sheath but didn't appear to have damaged the hypoglossal nerve or the vagus nerve, which control tongue function, the swallow reflex, and the voice box.
When the vagus nerve is severed, the enteric nervous system is capable of organizing and initiating its own reflexes for digestion because it has such a complex collection of neurons.
Researchers theorize that the misfolded protein sometimes travels up the vagus nerve to the brain, where it can affect cells involved with movement, causing the tremors that are a hallmark of Parkinson's.
The vagus nerve receives visceral sensory information from the thorax and abdomen, and the accessory nerve is responsible for innervating the sternocleidomastoid and trapezius muscles, neither of which is exclusively in the head.
Your diet affects which bacteria thrive, but as a result, the flourishing bacteria in your gut can then send signals to the brain via the vagus nerve to tell you to keep eating the foods they love.