I revisited the article I found after Shemaya mentioned the enteric brain to me. It’s densely biomedical, and I wouldn’t pretend to understand the actual chemistry involved, except that motility (the digestive action of the stomach and intestines) is linked to serotonin in some way. Serotonin is a neurotransmitter that has a lot to do with mood. Again, I don’t understand the actual reactions that stimulate sensation, but what I’ve been thinking about is the frequency with which &emdash; in my darker moments of the past couple of years &emdash; I’ve had the impulse to want to cut out my stomach. Rich said something similar the other night, about sometimes wanting to take a knife to his gut.
“Provided that the vagus nerve is intact, a steady stream of messages flows back and forth between the brain and the gut. We all experience situations in which our brains cause our bowels to go into overdrive. But in fact, messages departing the gut outnumber the opposing traffic on the order of about nine to one.”
In other words, just by quantity, the enteric system associated with the digestive tract produces many more messages than the brain. This leads me to think that the function of mind is to reconcile all of these messages. A task complicated by innumerable factors of genetics, socialization, exposure to various kinds of knowledge, and personal experiences.
The article is focused on physical phenomena, the material system that can be traced through careful scientific experimentation. I’m drawn to it because of the (oft repeated) phenomenological experience of emotional distress (grief, mostly) being accompanied by the urge to remove a part of my body. The article only mentions one example of an emotional-enteric connection:
“Correlation or Causation? Whatever the exact connection, the relationship between the cerebral and enteric brains is so close that it is easy to become confused about which is doing the talking. Until peptic ulcer was found to be an infectious disease, for example, physicians regarded anxiety as the chief cause. Now that we recognize Helicobacter pylori as the cause, it seems clear that the physical sensation of burning epigastric pain is generally responsible for the emotional symptoms, rather than the other way around. But because most ulcer patients, if questioned, will admit to feeling anxious, the misunderstanding persisted for decades.”