Nerves Within the Abdomen
The enteric nervous system (ENS) is a complex system of about 100 million nerves found in the lining of the gut. The ENS is sometimes called the “second brain,” and it actually arises from the same tissues as our central nervous system (CNS) during fetal development. Therefore, it has many structural and chemical parallels to the brain. Our ENS doesn’t wax philosophical or make executive decisions like the gray shiny mound in our skulls. Yet, in a miraculously orchestrated symphony of hormones, neurotransmitters, and electrical impulses through a pathway of nerves, both “brains” communicate back and forth. These pathways include and involve endocrine, immune, and neural pathways. At this point in time, even though the research is inchoate and complex, it is clear that the brain and gut are so intimately connected that it sometimes seems like one system, not two. – Jennifer Wolkin
Serotonin Primarily Manufactured in the Gut
Amazingly, if you were to isolate these neurons [in the gut] and clump them all together, they would form a mass of neurons larger than the ones in your head. In fact, the brain in your gut is way more active in the production of neurotransmitters than the brain in your head. Serotonin, the neurotransmitter responsible for the feeling of happiness and well-being, is primarily manufactured in the gut—90 percent of it, in fact. – Alejandro Junger M.D.
Can Work On Its Own + Send Signals to the Brain
The ENS can work all on its own, without any input from the brain, to control the movement and absorption of food throughout the intestines. No other organ can call its own tune… But the ENS — sometimes considered a branch of the autonomic nervous system, although Gershon sees it as holding its own — does much more than control itself. It also sends signals north to the brain that directly affect feelings of sadness or stress, even influencing memory, learning, and decision-making. It relies on, and in many cases manufactures, more than 30 neurotransmitters, including serotonin, that are identical to those in the brain. What’s more, tinkering with the second brain in our gut has lately been shown to be a potent tool for achieving relief from major depression. Even autism, studies suggest, may be wrapped up in the neurobiology of the brain down under. “The nervous system actually started out in the gut,” says Emeran Mayer, director of the UCLA Center for Neuro-visceral Sciences… Most of my patients have a very good understanding that there is a close connection between their emotions and their guts.”– Dan Hurley