The enteric nervous system is your second brain

Mood, decision-making and human behavior involve not only the brain, but also the gastrointestinal tract. In the human body, there is a separate nervous system, which is so complex that it is called the second brain. It consists of about 500 million neurons, and is about 9 meters long and runs from the esophagus to the anus.

It is this "brain" may be responsible for eating junk food during times of stress, mood changes, and some illnesses. It is about the enteric nervous system that estet-portal.com will tell in this article.

Enteral nervous system – Your "second brain"

In the walls of the gastrointestinal tract is the enteric nervous system (ENS), which, as previously believed, is involved exclusively in the control of the digestion process. Now, experts suggest that it plays an important role in the physical and mental state of a person. It can work autonomously and interact with the brain.

If you look inside the human body, it will be difficult not to notice the brain and the branches of nerve cells along the spine. ENS – a wide network of neurons located in two layers of intestinal tissue is less noticeable, and therefore was discovered only in the middle of the 19th century. It is part of the autonomic nervous system, a network of peripheral nerves that control the functions of internal organs.

For many years, people have believed that the gut interacts with the brain, affecting human health.

In addition to controlling the mechanical mixing of food in the stomach and coordinating muscle contractions to move food through the gastrointestinal tract, the ENS also maintains the biochemical environment in the various parts of the gastrointestinal tract, thereby maintaining the proper pH and chemistry required for digestive enzymes.

However, there is another reason why the ENS needs so many neurons – eating is fraught with danger. Bacteria and viruses that enter the gastrointestinal tract with food should not capture the body. If the pathogen penetrates the intestinal mucosa, immune cells will begin to secrete inflammatory substances, incl. histamine, which recognize ENS neurons. The second brain either triggers the diarrhea or tells the brain to cleanse in some other way – through vomiting (or both processes occur simultaneously).

For many years, people have believed that the gut interacts with the brain, affecting human health. However, it was possible to confirm such a connection relatively recently, when it became clear that the ENS can act autonomously, as well as with the opening of its main communication channel with the brain – vagus nerve. In fact, about 90% of the signals transmitted through the vagus nerve do not come from above (from the brain), but from below (from the ENS).

Second Brain – wellness factor

The second brain has many features in common with the first – it also consists of various types of neurons and glial support cells. It also has its own analogue of the blood-brain barrier, which maintains the stability of the physiological environment. The second brain also produces a range of hormones and about 40 neurotransmitters of the same classes as those produced in the brain.

Interestingly, about 95% of the serotonin in the body comes from the ENS.

What are the features and functions of the ENS?

1. Dopamine is a signaling molecule associated with feelings of pleasure and the reward system. In the gut, it also functions as a signaling molecule that relays messages between neurons and, for example, coordinates the contraction of colon muscles. Serotonin, which is produced in the gastrointestinal tract, enters the bloodstream and is involved in the restoration of damaged liver and lung cells. It is also necessary for the normal development of the heart and the regulation of bone density.
2. Mood. Clearly, the gut brain is not responsible for emotions. However, theoretically, neurotransmitters produced in the gastrointestinal tract can enter the hypothalamus. Nerve signals sent from the gastrointestinal tract to the brain can indeed influence mood. A study published in 2006 in The British Journal of Psychiatry found that vagus nerve stimulation may be effective in treating chronic depression.
3. "Butterflies in the stomach" are the result of blood flowing to the muscles as part of the fight-or-flight response triggered by the brain. However, stress also increases the production of ghrelin, which, in addition to increasing hunger, reduces anxiety and depression. Ghrelin stimulates the release of dopamine by acting on neurons involved in the pleasure and reward pathways, as well as through signals transmitted through the vagus nerve.

Specialists believe that problems with the ENS are associated with various diseases, so the second brain deserves much more attention from scientists. Control of obesity, diabetes, Alzheimer's and Parkinson's and other ailments – potential benefits of further study of the ENS.