The influence of the "second brain" in the intestine that makes me want to eat sweets when I am tired

ByKeith Rowley

Human behavior and thinking is thought to be based on commands from the brain, but when everything goes bad, there should be anyone who thought "to eat delicious things and get better". What is issuing this order is different from the brain in the head, "Second brainIt is said that it is a nervous system spreading in the intestine called " How does the intestine affect thinking?

Gut instincts: The secrets of your second brain

◆ What is the second brain?
A complex nervous system called "second brain" is connected from the esophagus to the anus, and the total length is about 9 meters. It is formed by 500 million neurons corresponding to 5 times the mouse brain, and seeking chocolate and fat-rich foods when feeling stress is an effect of this "second brain" Thing. A tissue that controls digestion of the intestinal nervous system is embedded in the intestinal wall, but the intestinal nervous system is said to be able to influence the behavior separately from the brain according to the change of the environment.

ByMichael Gil

The intestinal nervous system is a part of the autonomic nervous system expanding the distribution network of vast neurons, but it was not found until the 19th century because it was covered with two layers of intestinal tissue. It is thought that it was configured as a dedicated neural network that monitors complicated digestive processing, carries out such as feeding the food entering the stomach to the intestines by muscle contraction and maintaining the pH value in the intestine with chemical components I will. Furthermore, the intestinal nervous system requires 500 million neurons to prevent bacteria and viruses that may be carried along with meals. The intestinal nervous system detects passage of the pathogen through the intestine, and the immune cells of the intestinal wall secrete inflammatory substances including histamine. It is known that choosing diarrhea or vomiting to drain pathogenic bacteria also determines the intestinal nervous system, not the brain.

◆ Intestinal nervous system produces the same amount of dopamine as the brain
Various neurons andGlial cellsThe intestinal nervous system formed by, for example, synthesizes about 40 types of neurotransmitters that are about the same size as the brain,SerotoninOf the brain is always filled in the intestinal nervous system, as much as 95% of the brainDopamineIt is considered to be synthesizing. Dopamine is a neurotransmitter associated with pleasure and willingness, but in the intestine it acts as a molecule emitting signals between neurons regulating muscle contraction in the colon. Serotonin is a substance related to antidepressant / sleep / temperature regulation and "happiness feeling", but serotonin synthesized in the intestine has an important role of entering the blood and serving as repair when the liver and lungs are damaged I will.

It is a general theory that intestines are not affected by emotions by these substances and neurotransmitters synthesized in the intestines can not enter the brain, but in theory it includes the hypothalamusBlood brain barrierIt is also said that you can go through, there is also the possibility of influencing emotions from the brain. According to research published in 2006, it distributes to the abdomenVagus nerveIt shows that stimulation to chronic depression is effective.

Also,Study published at medical journal JCI, Subjects given fatty acids know that the response to weak music and photographs is weaker than subjects given physiological saline. According to another study published in JCI magazine, when the brain feels hungry, it is involved in promoting appetite and anxiety in the intestineGhrelinIt will come to generate. Ghrelin promotes the release of dopamine in the brain, so that when you feel tired or stress you feel better with foods that contain a lot of fat, the neurotransmitters from the intestines are affecting the brain It is predicted that it may not be the case.

Intestinal instinct
The second brain, the intestinal nervous system, does not affect human decision-making, and it is the brain that perceives fear when it is forced to make a decision such as "do bungee jumping or postpone" . However, in one experiment, we gave a weak chemical substance to the stomach of a newly born mouse, where signs of depression and anxiety became larger than other rats, such as when a physical danger approached. Potential "intestinal instinct" that the intestine itself affects emotions is being established.

"Psychosis that the intestine falls"
Although the intestinal nervous system has various influences on the human body besides digestion, this "second brain" may be related to numerous brain diseases. Parkinson's disease is said to be caused by damage of cells producing dopamine in the brain,University of FrankfurtHeiko Braak of Mr. is said to be involved in Parkinson's diseaseLewy bodyPointed out that a group of proteins called "neurons" appear in the intestinal dopamine producing neurons. As a result of investigating the distribution of Lewy bodies of people who died of Parkinson's disease, we judged that the source of Levi - body was intestine and invaded the brain through the vagus nerve with virus etc.

ByAndy Wilkinson

The tendency of gastrointestinal disorders in autistic patients is thought to be due to the influence of both brain and intestinal neurons due to mutations in genes affecting the brain. In this way, diseases of the brain may affect the intestines,Johns Hopkins UniversityPankaj Pasricha, on the contrary, suggests that the cells of the intestinal nervous system may be used to treat diseases of the brain. Although it is necessary to transplant neural stem cells to compensate for neurons lost in neurodegenerative diseases, it is not easy to collect these cells from the brain or spinal cord. "In theory, it may be possible to collect cells that can be transplanted from the intestinal biopsy to the brain by simple endoscopy," and if successful, it can be used for treatment such as treatment of Parkinson's disease It is.

in Science, Posted by darkhorse_log