Your Gut Has a Mind of Its Own... Literally
Tummies talk to us. Whether it is from pangs of hunger or a sensation of satiety, our guts like to keep in contact. For the longest time, I considered this "communication" to be no more than intelligible mumbling. But a somewhat recent discovery has got me thinking about those burps, bubbles, and gurgles in a whole new light. Because, as it turns out, your gut has a mind of its own.
Termed the "Second Brain" by Dr. Michael Gershon, the enteric nervous system is a collection of over 100 million neurons embedded within the lining of the gastrointestinal system. While this amount of neurons actually pales in comparison to the brain's 100 billion, the neural tissue formed by these neurons constitutes an intricate and autonomous system that plays a big role in all vertebrates.
Scientists theorize that the enteric nervous system originally evolved to locally control motility, blood flow and secretion in the digestive system. This way, "The brain in the head doesn't need to get its hands dirty with the
messy business of digestion," Gershon told Scientific American. Two brains, it seems, are better than one.
Besides managing digestion, the "second brain" appears to partly regulate our mood. Well over 90% of serotonin -- a neurotransmitter thought to contribute to well-being -- is found within the gut, and its presence clearly factors in to the workings of the enteric nervous system. Too much serotonin can overwhelm the system's receptors, causing irritable bowel syndrome, while too little serotonin presents its own array of problems.
Since the enteric nervous system is connected to the brain via the vagus nerve, Dr. Emeran Mayer, a professor at UCLA, says that "A big part of our emotions are probably influenced by the nerves in our gut."
And remember, humans aren't the only lifeforms whose emotions can be influenced by the "second brain." This fact has renowned canine behaviorist Dr. Patricia McConnell saying, "Wow," and also considering what this means for our dogs.
"How many of you have seen dogs who have digestion problems who also have
behavior problems related to emotional control (especially fear)?," McConnell asked on her blog. "I can't tell you how many dogs I've seen as clients who had both problems, and whose treatment ended up effecting both systems."
Further studies are undoubtedly needed to fully examine the functions of the enteric nervous system in both humans and critters.