People's gastrointestinal system is far away from the brain, and communication and dialogue with the brain is usually considered to be through the release of hormones.

According to previous medical research, the gastrointestinal system releases hormones into the blood by digesting food. In the process of about 10 minutes, the hormones taken away by the blood communicate with the brain and tell whether the brain is still hungry. Then the brain sends out inhibition instructions, telling us not to eat too much or continue to eat.

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A recent study published in the journal Cell shows that our gastrointestinal system may have a set of neural circuits that communicate directly with the brain, which can transmit signals from the gastrointestinal tract to the brain in a few seconds.

This neural circuit, the yellow spiral columnar neural circuit shown above, the vagus sympathetic nerve in the gastrointestinal tract, tells the brain what our stomach is doing at once.

These findings may play an important role in the future medical treatment of diseases related to gastrointestinal diseases, such as obesity, eating disorders, depression and autism.

The researchers believe that although many important clinical significance is still unclear, Daniel Drucker, a clinical scientist at Lunenfield Talent Institute in Toronto, said: "This study reveals a new channel for rapid communication between the gastrointestinal tract nucleus and the brain, which is a brand-new discovery." (Daniel Drucker, clinical scientist, Lunenfeld-Tanenbaum Institute, Toronto, Canada)

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20 10 Diego Bohorquez, a neuroscientist at Duke University in Durham, North Carolina, made an amazing discovery when he carefully examined his electron microscope.

Intestinal endocrine cells scattered in the gastrointestinal tract usually produce hormones to stimulate absorption and inhibit hunger, and there are some podiform processes around the cells, which communicate with each other like synaptic nerves.

Bohokoz knows that endocrine cells in the gastrointestinal tract can produce hormone information and transmit it to the central nervous system. At the same time, he is also curious about whether these endocrine cells in the gastrointestinal tract can directly talk to the brain with electrical signals in addition to hormones. If the hypothesis is true, they need to send vagus nerve through the gastrointestinal tract to connect to the main brain.

In order to test the hypothesis, Bohokoz injected mice with fluorescent rabies virus, which was transmitted to the large intestine of mice through synapses, waiting for intestinal secretory cells and their partners to glow. (intestinal endocrine cells, transmitted through neuronal synapses) The companion of these intestinal secretory cells is vagus nerve.

In Petri dishes, intestinal secretory cells extend to vagus nerve cells and then correlate with each other. These intestinal secretory cells even secrete glutamic acid, which is a neurotransmitter involved in smell and taste. Vagal cells receive it quickly in 100 milliseconds (100 milliseconds), faster than blinking. Then it travels along the vagus nerve circuit, the yellow line in the above picture, to the brain.

This transmission speed is much faster than previously known that intestinal secretory cells release hormones into the blood, and the blood circulates in the body and then exchanges information with the brain. The slow response of this hormone exchange system (about 10 minute) may be an important reason for the failure of many targeted weight-loss drugs-appetite suppressants.

Next, Bohokoz's research will focus on whether these gastrointestinal signals provide the brain with some information about the nutritional composition and calories of food in the gastrointestinal tract.

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This ultra-fast information transmission between the gastrointestinal tract and the brain has many advantages, such as detecting toxins and poisons that may be contained in food.

Bohokz also speculated that there may be other kinases (perks) sensing the contents of our gastrointestinal tract. Sensory cells in the gastrointestinal tract can be traced back to multicellular organisms, and a kind of organism called Trichoplax adhaerens first existed about 600 million years ago.

Another study published in the journal Cell also provides information on how intestinal sensory cells are beneficial to people. The researchers used laser to stimulate the sensory nerve cells in the gastrointestinal tract of mice and activated these nerve sensory cells. (Nerve innervates those sensory neurons), which can give rodents incentives to work repeatedly. The researchers found that laser stimulation can also produce dopamine neurotransmitters in the brains of rodents, which can improve the emotional level of rodents.

Ivan de Araujo of icahn school of medicine at mount sinai, new york, believes that the above two findings can explain why stimulating vagus nerve with electric current can treat major depression.

These studies can also help explain why food can make us feel so good, because even though these gastrointestinal tract secretes nuclear vagus nerve cells, although they are distributed outside the brain, they are suitable as reward nerves of the body, driving food incentives and enhancing the body's pleasure.

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There are many unsolved mysteries in the human body. The cooperation between vagus nerve and secretory cells of gastrointestinal tract opens up a fast channel from gastrointestinal tract to brain, which has great scientific and health care value.

From the previously known hormone channel between the gastrointestinal tract and the brain (it takes about 10 minutes to realize the dialogue), a second fast communication channel was found (the reaction of the gastrointestinal tract to food digestion and decomposition can be reported to the brain in a blink of an eye or in a few seconds).

Medically speaking, it can open up a new field, the direct connection between gastrointestinal research and brain, and consider two seemingly distant organs and related diseases.

In terms of health, what to eat and how to eat are really important. Maintaining the health of gastrointestinal tract is of great significance to fight obesity and depression, two common diseases of modern people.

Conversely, from a health point of view, keeping the gastrointestinal tract healthy can prevent obesity and depression, as well as autism in the elderly.