Poisonous and highly toxic substances with neurotoxic effects. What are neurotoxins? Neurotoxins mechanism of action

>>>> What are the dangers of neurotoxic effects?

What are the dangers of neurotoxic effects?

A number of substances can have a detrimental effect on nerve fibers, and such substances are called neurotoxins, and their results are called neurotoxic disorders. Neurotoxins can cause acute reactions or delayed action, turning the toxic effect into a chronic process.

Chemical reagents, anesthetics, antiseptics, detergents, pesticides, insecticides, metal fumes, and drugs with neurotoxic side effects can act as neurotoxins. Neurotoxic effects can begin when the components of these substances accidentally enter the respiratory system, into the blood, and when their permissible concentration in the blood is exceeded.

Neurotoxic effects substances on the body manifests itself in a number of signs:

Headache,
dizziness,
Feeling faint
Weakness of the muscles of the limbs,
Balance disorders
Feeling of tissue numbness,
Tissue sensitivity disorders
Slow or impaired reflexes
Cardiac disturbances (arrhythmias, tachycardia),
Visual impairment,
Breathing disorders
Pain similar to radicular syndrome,
Movement disorders
Urinary retention or urinary incontinence,
Confusion.

Neurotoxic disorders may be reversible and disappear when the action of the neurotoxin ceases, but they can also lead to irreversible damage in the body.

You can be exposed to neurotoxic effects:

in the production of chemicals, being in a harmful atmosphere for a long time,
when working with fertilizers and insecticides in agriculture and on private summer cottages,
when carrying out disinfection of premises, being in an atmosphere filled with vapors of a concentrated disinfectant,
during repair and construction work with paints and varnishes, adhesives, solvents in poorly ventilated areas,
being near a combustion zone with a high concentration of carbon monoxide,
Being in the zone of a chemical man-made disaster (emergency releases).

Neurotoxic disorders can over time transform into diseases of the nervous system and musculoskeletal system: myopathies, Parkinson's disease, decreased or loss of vision, dysfunction of the vestibular apparatus, mental degradation, tics, tremor.

Treatment of neurotoxic disorders is based on carrying out detoxification measures to remove toxic substances from the body and reduce their concentration in tissues, restore water and electrolyte balance, and cleanse the blood of toxins through hemosorption. In case of neurotoxicosis, symptomatic therapy is carried out (anticonvulsants, muscle relaxants, anti-inflammatory drugs, antiallergic drugs) to eliminate disorders that appear as a result of toxic effects. The priority direction in the treatment of neurotoxic disorders is the restoration of respiratory activity, hemodynamics, and the prevention of cerebral edema. Next, the affected organs are monitored, appropriate treatment is prescribed and motor activity is restored.

Neurotoxins are botulinum toxin, poneratoxin, tetrodotoxin, batrachotoxin, components of the venoms of bees, scorpions, snakes, and salamanders.

Potent neurotoxins, such as batrachotoxin, affect the nervous system by depolarizing nerves and muscle fibers, increasing the permeability of the cell membrane to sodium ions.

Many poisons and toxins used by organisms to defend against vertebrates are neurotoxins. The most common effect is paralysis, which occurs very quickly. Some animals use neurotoxins when hunting, since paralyzed prey becomes convenient prey.

Sources of neurotoxins

External

Neurotoxins coming from the external environment are classified as exogenous. Can be gases (for example, carbon monoxide, BOM), metals (mercury, etc.), liquids and solids.

The effects of exogenous neurotoxins once they enter the body are highly dependent on their dose.

Domestic

Substances produced within the body can be neurotoxic. They're called endogenous neurotoxins. An example is the neurotransmitter glutamate, which is toxic at high concentrations and leads to apoptosis.

Classification and examples

Channel inhibitors

Nerve agents

Alkyl derivatives of methylfluorophosphonic acid: sarin, soman, cyclosarin, ethylzarin.

Cholinethiophosphonates and cholinephosphonates: V-gases.

Other similar compounds: herd.

Neurotoxic drugs

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Notes

Although only substances of biological origin are toxins, the term Neurotoxin also applies to synthetic poisons. "Natural and synthetic neurotoxins", 1993, ISBN 978-0-12-329870-6, sect. “Preface”, quote: “Neurotoxins are toxic substances with selective actions on the nervous system. By definition, toxins are of natural origin, but the term "neurotoxin" has been widely applied to some synthetic chemicals that act selectively on neurons"
Kuch U, Molles BE, Omori-Satoh T, Chanhome L, Samejima Y, Mebs D (September 2003). "". Toxicon 42 (4): 381–90. DOI:. PMID 14505938.
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Moser, Andreas.. - Boston: Birkhäuser, 1998. - ISBN 0-8176-3993-4.
Turner J. J., Parrott A. C.(English) // Neuropsychobiology. - 2000. - Vol. 42, no. 1 . - P. 42-48. - DOI: [ Error: Invalid DOI!] . - PMID 10867555.
Steinkellner T., Freissmuth M., Sitte H. H., Montgomery T.(English) // Biological chemistry. - 2011. - Vol. 392, no. 1-2. - P. 103-115. - DOI:. - PMID 21194370.
Abreu-Villaça Y., Seidler F. J., Tate C. A., Slotkin T. A.(English) // Brain research. - 2003. - Vol. 979, no. 1-2. - P. 114-128. - PMID 12850578.
Pedraza C., García F. B., Navarro J. F.(English) // The international journal of neuropsychopharmacology / official scientific journal of the Collegium Internationale Neuropsychopharmacologicum (CINP). - 2009. - Vol. 12, no. 9 . - P. 1165-1177. - DOI:. - PMID 19288974.

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Excerpt describing Neurotoxin

Six months after my grandfather's death, an event occurred that, in my opinion, deserves special mention. It was a winter night (and winters in Lithuania at that time were very cold!). I had just gone to bed when I suddenly felt a strange and very soft “calling”. It was as if someone was calling me from somewhere far away. I got up and went to the window. The night was very quiet, clear and calm. The deep snow cover shone and shimmered with cold sparks throughout the sleeping garden, as if the reflection of many stars was calmly weaving its sparkling silver web on it. It was so quiet, as if the world had frozen in some strange lethargic sleep...
Suddenly, right in front of my window, I saw the glowing figure of a woman. It was very tall, over three meters, absolutely transparent and sparkled, as if it was woven from billions of stars. I felt a strange warmth emanating from her, which enveloped me and seemed to call me somewhere. The stranger waved her hand, inviting him to follow her. And I went. The windows in my room were very large and low, non-standard by normal standards. At the bottom they reached almost to the ground, so I could freely crawl out at any time. I followed my guest without the slightest fear. And what was very strange was that I didn’t feel the cold at all, although it was twenty degrees below zero outside at that moment, and I was only in my children’s nightgown.
The woman (if you can call her that) again waved her hand, as if inviting him to follow her. I was very surprised that the normal “moon road” suddenly changed its direction and “followed” the stranger, as if creating a luminous path. And I realized that I had to go there. So I followed my guest all the way to the forest. Everywhere there was the same aching, frozen silence. Everything around sparkled and shimmered in the silent glow of moonlight. The whole world seemed to freeze in anticipation of what was about to happen. The transparent figure moved on, and I, as if spellbound, followed it. The feeling of cold still did not appear, although, as I later realized, I had been walking barefoot all this time. And what was also very strange was that my feet did not sink into the snow, but seemed to float along the surface, leaving no traces on the snow...
Finally we came to a small round clearing. And there... illuminated by the moon, unusually tall, sparkling figures stood in a circle. They were very similar to people, only absolutely transparent and weightless, just like my unusual guest. They were all wearing long, flowing robes that looked like shimmering white cloaks. The four figures were male, with completely white (possibly gray), very long hair, intercepted by brightly glowing hoops on the forehead. And two female figures who were very similar to my guest, with the same long hair and a huge sparkling crystal in the middle of the forehead. The same calming warmth emanated from them and I somehow understood that nothing bad could happen to me.

I don’t remember how I found myself in the center of this circle. I only remember how suddenly brightly glowing green rays came from all these figures and connected right on me, in the area where my heart should have been. My whole body began to quietly “sound”... (I don’t know how it would be possible to more accurately define my state at that time, because it was precisely the sensation of sound inside). The sound became stronger and stronger, my body became weightless and I hung above the ground just like these six figures. The green light became unbearably bright, completely filling my entire body. There was a feeling of incredible lightness, as if I was about to take off. Suddenly a dazzling rainbow flashed in my head, as if a door had opened and I saw some completely unfamiliar world. The feeling was very strange - as if I had known this world for a very long time and at the same time, I had never known it.

What are neurotoxins? These are substances that interfere with the electrical activity of the nerves, preventing them from working properly.

How do neurotoxins destroy nerve cells?

Neurotoxins are substances that interact with nerve cells, overstimulating them or interrupting communication between them. These are harmful processes for nerve cells that affect their chemical processes. Research clearly shows that neurotoxins reduce the life of nerve cells. These toxins are associated with various brain disorders and neurodegenerative diseases such as Alzheimer's disease, Huntington's chorea and Parkinson's disease.

Neurotoxins have proliferated significantly over the past few decades. Many of them are used in the food we eat and the water we drink. The most widely used neurotoxins are in fast food, canned foods, and are also often used in infant formula.

Neurotoxins in food

If you have a child or toddlers, you should pay special attention to the 10 most common neurotoxins listed below. Children are most vulnerable to neurotoxins because their bodies are still developing. Processed foods such as chips, candy and chocolate often contain neurotoxins. If you encounter food containing any of the neurotoxins listed below, you should avoid eating it.

Aspartame (aka Equal, AminoSweet, NutraSweet, Spoonful) - Most often used in sugar-free foods. Especially in chewing gums and sugar-free drinks. Most aspartame is obtained from the waste of genetically modified bacteria. Research shows that aspartame can cause diabetes, migraines, kidney failure, seizures, blindness, obesity, neurological disorders, mental illness and brain tumors.

Monosodium glutamate (also known as MSG) is most commonly used in chips, canned food, baby food and a number of unhealthy foods. Independent researchers believe that MSG plays an important role in the development of neurodegenerative brain diseases, including Alzheimer's, Parkinson's and Huntington's diseases. Evidence supporting this claim comes from the fact that monounsaturated grutans damage neurons, especially brain cells.

Sucralose (also known as Splenda) is an artificial sweetener used in sugar-free products, especially beverages. Sucralose was discovered quite by accident while research was being done to create a new insecticide. Therefore, many scientists believe that sucralose should be considered as an insecticide. This toxin is identified by many as the chemical cousin of DDT. Sucralose is a chlorinated compound, and the breakdown of this type of compound in the body releases toxic chemicals.

Aluminum – This metal is common in drinking water and vaccines. Aluminum is highly absorbed by the body. Citric acid or citrate can significantly increase its absorption. Vaccines are one of the main causes of aluminum toxicity because aluminum is injected directly into the body.

Mercury - this heavy metal is common in fish products and vaccines. Mercury can also be found in drinking water. It is one of the most toxic neurotoxins because it easily destroys brain tissue.

Fluoride (sodium fluoride). This toxin is very common in drinking water and regular toothpastes. In the past, fluoride was used as a rat poison. Fluoride used in consumer products is a mixture of very dangerous chemicals. Also known as sodium fluoride, it does not mix with naturally occurring calcium fluoride. For this reason, fluoride toothpastes have warning labels.

Hydrolyzed Vegetable Protein – This unhealthy food ingredient is common in most unhealthy foods. It contains high concentrations of glutamate and aspartate, which can stimulate nerve cells and ultimately lead to their death.

Calcium caseinate – This toxin is commonly used in protein supplements, junk foods, and chocolate energy drinks. It damages the brain due to its neurotoxic properties.

Sodium caseinate – This type of protein is common in dairy products and junk foods. It is believed to cause problems with autism and gastrointestinal diseases.

Yeast extract is a popular food ingredient in many processed foods such as canned foods. It is toxic to the brain.

Some substances can have extremely negative effects on human health. Natural or synthetic poisons affect the kidneys, liver, heart, damage blood vessels, causing bleeding, or act at the cellular level. Neurotoxins are substances that damage nerve fibers and the brain, and the results of such toxins are called neurotoxic disorders. The impact of this kind of poisons can be either delayed or cause acute conditions.

What are neurotoxins and where are toxic substances used?

Neurotoxins can be chemicals, drugs that cause anesthesia, antiseptics, metal fumes, aggressive detergents, pesticides and insecticides. Some living organisms are capable of producing neurotoxins in response to a threat to the immune system, and numerous toxic substances are present in the environment.

According to scientific research data summarized in the publication of the authoritative weekly medical journal “The Lancet,” about two hundred toxins can damage the human nervous system. Later (after studying data from the National Institute of Occupational Safety), it became necessary to add to the published list the same number of toxic substances that in one way or another have a negative effect on the central nervous system.

In the latter case, damage to nerve fibers was combined with damage to associated organs and systems, and symptoms of a neurotoxic disorder appeared when permissible exposure limits were exceeded.

Thus, the list of chemicals that can be classified as neurotoxins expands depending on what criteria a particular publication or author adheres to.

You can get neurotoxin poisoning by inhaling toxic fumes, increasing the permissible concentration in the blood, or eating foods saturated with large amounts of toxic substances. Many toxic substances are present in the environment, consumer goods, and household chemicals. Neurotoxins are used in cosmetology, medicine and industry.

What is the neurotoxic effect on the body?

Neurotoxic effects primarily affect the brain and nerve fibers. Neutralization of the work of cells in the nervous system can lead to muscle paralysis, the occurrence of an acute allergic reaction, and affects the general mental state of a person. In severe cases, poisoning can cause coma and be fatal.

Toxic substances of this kind are absorbed into nerve endings, transmitted to cells and disrupt vital functions. The body's natural detoxification mechanisms are practically powerless against neurotoxins: in the liver, for example, the main functional feature of which is the elimination of harmful substances, most neurotoxins, due to their specific nature, are reabsorbed by nerve fibers.

Neurotoxic poison can complicate the course of any disease, which makes definitive diagnosis and timely treatment difficult.

Establishing an accurate diagnosis necessarily includes determining the suspected source of infection, studying the history of contact with a potential poison, identifying the full clinical picture and conducting laboratory tests.

Classification of the most famous representatives of neurotoxins

Medical sources classify neurotoxins into channel inhibitors, nerve agents, and neurotoxic drugs. Based on their origin, toxic substances are divided into those obtained from the external environment (exogenous) and those produced by the body (endogenous).

The classification of neurotoxins, poisoning from which is likely to occur at work and at home, includes three groups of the most common substances:

Heavy metals. Mercury, cadmium, lead, antimony, bismuth, copper and other substances are quickly absorbed into the digestive tract, carried through the bloodstream to all vital organs and deposited in them.
Biotoxins. Biotoxins include potent poisons that are produced, in particular, by marine life and spiders. Substances can penetrate mechanically (by a bite or injection) or by eating poisonous animals. In addition, botulism bacteria are biotoxins.
Xenobiotics. A distinctive feature of this group of neurotoxins is their prolonged effect on the human body: the half-life of dioxin, for example, ranges from 7 to 11 years.

Symptoms of neurotoxin damage

Neurotoxic disorders caused by toxic substances are characterized by a number of symptoms typical of poisoning in principle, and specific signs that occur during intoxication with a particular compound.

Heavy metal intoxication

Thus, patients experience the following signs of heavy metal intoxication:

abdominal discomfort;
bloating, diarrhea, or constipation;
nausea and occasional vomiting.

At the same time, poisoning with a specific metal has its own distinctive characteristics. Thus, with mercury intoxication, a metallic taste is felt in the mouth, increased salivation and swelling of the lymph nodes are characteristic, and it is characterized by a strong cough (sometimes with blood), lacrimation, and irritation of the mucous membranes of the respiratory tract.

A severe case is: anemia develops, the skin becomes bluish, and the functioning of the liver and kidneys is quickly disrupted.

Biotoxin poisoning

In case of poisoning with biotoxins, the first signs of intoxication may include:

increased salivation, numbness of the tongue, loss of sensation in the legs and arms (typical of poisoning with tetrodotoxin contained in puffer fish);
increasing abdominal pain, nausea and vomiting, bowel irregularities, spots before the eyes and respiratory failure (botulinum toxin intoxication);
severe pain in the heart, hypoxia, paralysis of internal muscles (a condition similar to a heart attack occurs when poisoned with batrachotoxin contained in the glands of some species of frogs).

Intoxication with xenobiotics

A neurotoxic poison of anthropogenic origin is dangerous because symptoms of intoxication can appear over a long period of time, which leads to chronic poisoning.

Damage from formaldehyde or dioxins - by-products of the production of pesticides, paper, plastics, etc. - is accompanied by the following symptoms:

loss of strength, fatigue, insomnia;
abdominal pain, loss of appetite and exhaustion;
irritation of the mucous membranes of the mouth, eyes and respiratory tract;
nausea, vomiting blood, diarrhea;
impaired coordination of movements;
anxiety, delirium, feeling of fear.

Features of neurotoxin poisoning

A distinctive feature of neurotoxins is damage to the human nervous system.

Thus, the patient’s condition is characterized by:

impaired coordination of movements;
slowing brain activity;
disturbances of consciousness, memory loss;
throbbing headache;
darkening of the eyes.

As a rule, the general symptoms include symptoms of poisoning from the respiratory, digestive and cardiovascular systems. The specific clinical picture depends on the source of intoxication.

Prevention of intoxication at work and at home

Prevention of poisoning largely depends on the nature of the potential threat. So, in order to avoid intoxication with biotoxins, food should be thoroughly cooked, avoid eating expired or low-quality products, and prevent contact with potentially poisonous animals and plants. Heavy metal poisoning can be prevented by using products made from these materials strictly for their intended purpose, observing safety measures when working in hazardous industries and sanitary rules.

Leonid Zavalsky

Neurotoxins are increasingly used in medicine for therapeutic purposes.

Some neurotoxins with different molecular structures have a similar mechanism of action, causing phase transitions in the membranes of nerve and muscle cells. Hydration plays an important role in the action of neurotoxins, which significantly affects the conformation of interacting poisons and receptors.

Information about the poisonousness of pufferfish (maki-maki, dogfish, puffer fish, etc.) dates back to ancient times (more than 2500 years BC). Of the Europeans, the first to give a detailed description of the symptoms of poisoning was the famous navigator Cook, who, along with 16 sailors, treated himself to pufferfish during his second voyage around the world in 1774. He was lucky, because he “barely touched the fillet,” while “the pig, which ate the entrails, died.” Oddly enough, the Japanese cannot deny themselves the pleasure of tasting this, from their point of view, delicacy, although they know how carefully it should be prepared and how dangerous it is to eat.

The first signs of poisoning appear within a few minutes to 3 hours after eating fugu. At first, the unlucky eater feels a tingling and numbness of the tongue and lips, which then spreads to the whole body. Then a headache and stomach pain begin, and my arms become paralyzed. The gait becomes unsteady, vomiting, ataxia, stupor, and aphasia appear. Breathing becomes difficult, blood pressure decreases, body temperature drops, and cyanosis of the mucous membranes and skin develops. The patient falls into a comatose state, and soon after breathing stops, cardiac activity also stops. In a word, a typical picture of the action of a nerve poison.

In 1909, Japanese researcher Tahara isolated the active principle from fugu and named it tetrodotoxin. However, only 40 years later it was possible to isolate tetrodotoxin in crystalline form and establish its chemical formula. To obtain 10 g of tetrodotoxin, the Japanese scientist Tsuda (1967) had to process 1 ton of fugu ovaries. Tetrodotoxin is a compound of aminoperhydroquinazoline with a guanidine group and has extremely high biological activity. As it turned out, it is the presence of the guanidine group that plays a decisive role in the occurrence of toxicity.

Simultaneously with the study of the venom of rock-toothed fish and pufferfish, many laboratories around the world studied toxins isolated from the tissues of other animals: salamanders, newts, poisonous toads and others. It turned out to be interesting that in some cases, tissues of completely different animals that have no genetic relationship, in particular the Californian newt Taricha torosa, fish of the genus Gobiodon, Central American frogs Atelopus, Australian octopuses Hapalochlaena maculosa, produced the same poison tetrodotoxin.

The action of tetrodotoxin is very similar to another non-protein neurotoxin, saxitoxin, produced by unicellular flagellated dinoflagellates. The poison of these flagellated unicellular organisms can be concentrated in the tissues of mussel mollusks during mass reproduction, after which the mussels become poisonous when consumed by humans. A study of the molecular structure of saxitoxin showed that its molecules, like tetrodotoxin, contain a guanidine group, even two such groups per molecule. Otherwise, saxitoxin has no common structural elements with tetrodotoxin. But the mechanism of action of these poisons is the same.

The pathological effect of tetrodotoxin is based on its ability to block the conduction of nerve impulses in excitable nerve and muscle tissues. The uniqueness of the action of the poison lies in the fact that in very low concentrations - 1 gamma (one hundred thousandth of a gram) per kilogram of a living body - it blocks the incoming sodium current during the action potential, which leads to death. The poison acts only on the outside of the axon membrane. Based on these data, Japanese scientists Kao and Nishiyama hypothesized that tetrodotoxin, the size of the guanidine group of which is close to the diameter of the hydrated sodium ion, enters the mouth of the sodium channel and gets stuck in it, being stabilized on the outside by the rest of the molecule, whose dimensions exceed the diameter of the channel. Similar data were obtained when studying the blocking effect of saxitoxin. Let's consider the phenomenon in more detail.

At rest, a potential difference of approximately 60 mV is maintained between the inner and outer sides of the axon membrane (the outside potential is positive). When the nerve is excited at the point of application in a short time (about 1 ms), the potential difference changes sign and reaches 50 mV - the first phase of the action potential. After reaching the maximum, the potential at a given point returns to the initial state of polarization, but its absolute value becomes slightly greater than at rest (70 mV) - the second phase of the action potential. Within 3-4 ms, the action potential at this point on the axon returns to its resting state. The short circuit impulse is sufficient to excite the adjacent section of the nerve and repolarize it at the moment when the previous section returns to equilibrium. Thus, the action potential propagates along the nerve in the form of an undamped wave traveling at a speed of 20-100 m/s.

Hodgkin and Huxley and their co-workers studied in detail the process of propagation of nervous excitations and showed that in the resting state the axon membrane is impermeable to sodium, while potassium diffuses freely through the membrane. Potassium “flowing” out carries away a positive charge, and the internal space of the axon becomes negatively charged, preventing further release of potassium. As a result, it turns out that the potassium concentration outside the nerve cell is 30 times less than inside. With sodium, the situation is the opposite - in the axoplasm its concentration is 10 times lower than in the intercellular space.

Tetrodotoxin and saxitoxin molecules block the sodium channel and, as a result, prevent the passage of an action potential through the axon. As can be seen, in addition to the specific interaction of the guanidine group with the mouth of the channel (interaction of the “key-lock” type), a certain function in the interaction is performed by the remaining part of the molecule, subject to hydration by water molecules from the aqueous-salt solution surrounded by the membrane.

The importance of studies of the action of neurotoxins can hardly be overestimated, since for the first time they allowed us to get closer to understanding such fundamental phenomena as the selective ion permeability of cell membranes, which underlies the regulation of the vital functions of the body. Using highly specific binding of tritium-labeled tetrodotoxin, it was possible to calculate the density of sodium channels in the axonal membrane of different animals. Thus, in the squid giant axon the channel density was 550 per square micrometer, and in the frog sartorius muscle it was 380.

Specific blocking of nerve conduction allowed the use of tetrodotoxin as a powerful local anesthetic. Currently, many countries have already established the production of painkillers based on tetrodotoxin. There is evidence of a positive therapeutic effect of neurotoxin drugs in bronchial asthma and convulsive conditions.

The mechanisms of action of morphine drugs have now been studied in great detail. Medicine and pharmacology have long known the properties of opium to relieve pain. Already in 1803, the German pharmacologist Fritz Serthuner managed to purify the opium drug and extract the active principle from it - morphine. The drug morphine was widely used in clinical practice, especially during the First World War. Its main disadvantage is the side effect, which is expressed in the formation of chemical dependence and the body’s addiction to the drug. Therefore, attempts were made to find a replacement for morphine with an equally effective painkiller, but without side effects. However, all new substances, as it turned out, also cause addiction syndrome. This fate befell heroin (1890), meperidine (1940) and other morphine derivatives. The abundance of opiate molecules differing in shape provides the basis for accurately establishing the structure of the opiate receptor to which the morphine molecule is attached, similar to the tetrodotoxin receptor.

All molecules of analgesically active opiates have common elements. The opium molecule has a rigid T-shape, represented by two mutually perpendicular elements. At the base of the T-molecule there is a hydroxyl group, and at one end of the horizontal bar there is a nitrogen atom. These elements form the “basic basis” of the key that opens the receptor-lock. It seems significant that only levorotatory isomers of the morphine series have analgesic and euphoric activity, while dextrorotatory isomers are deprived of such activity.

Numerous studies have established that opiate receptors exist in the bodies of all vertebrate animals without exception, from sharks to primates, including humans. Moreover, it turned out that the body itself is capable of synthesizing opium-like substances called enkephalins (methionine-enkephalin and leucine-enkephalin), consisting of five amino acids and necessarily containing a specific morphine “key”. Enkephalins are released by special enkephalin neurons and cause the body to relax. In response to the attachment of enkephalins to the opiate receptor, the control neuron sends a relaxation signal to the smooth muscles and is perceived by the oldest formation of the nervous system - the limbic brain - as a state of supreme bliss, or euphoria. Such a state, for example, can occur after the end of stress, a well-done job or deep sexual satisfaction, requiring a certain mobilization of the body's forces. Morphine excites the opiate receptor, like enkephalins, even when there is no reason for bliss, for example, in case of illness. It has been proven that the state of nirvana of yogis is nothing more than euphoria achieved by the release of enkephalins through auto-training and meditation. In this way, yogis open access to smooth muscles and can regulate the functioning of internal organs, even stop the heartbeat.