A doctor at the Feinstein Institute for Medical Research has found that stimulating the vagus nerve can short-circuit the body's inflammation response.
According to the article in Science Daily,
[Kevin Tracey] discovered that the vagus nerve speaks directly to the immune system through a neurochemical called acetylcholine. And stimulating the vagus nerve sent commands to the immune system to stop pumping out toxic inflammatory markers. "This was so surprising to us," said Dr. Tracey, who immediately saw the potential to use vagus stimulation as a way to shut off abnormal immune system responses. He calls this network "the inflammatory reflex."
Why am I covering this in a blog about oxytocin?
It's because the vagus nerve is a major pathway between the body and the brain, and it's also an oxytocin highway. Remember, oxytocin is an anti-inflammatory, anti-stress hormone.
When the intestines begin to digest fat, they secrete cholecystokinin (CCK). CCK travels along the vagus nerve to the brain, where it stimulates the release of oxytocin. Oxytocin travels back down to the stomach, causing its walls to contract and creating that full-belly feeling.
The vagus also acts as an alternate pathway between the genitals and the brain. When Beverly Whipple, Barry Komisaruk and Carlos Beyer-Flores of Rutgers studied the sexual responses of women with spinal cord injuries, they found that even though they couldn't move or feel anything down there, they still were able to have orgasms.
They found that sexual stimulation bypassed the spinal cord and went directly from the genitals to the brain via the vagus nerve. Nerves from the mammary glands, uterus and skin, especially the chest, also connect directly to this sensory superhighway. These vagal signals stimulated the brain's reward, emotion and memory systems, causing the release of oxytocin, as well as exciting dopamine and rewarding opioids.
Tracey may not be studying oxytocin, but I'd bet that stimulating the vagus causes the release of oxytocin, and it's that which cools out the inflammatory response.
For more on oxytocin's role in eating, see The Sex/Food/Love Connection.