Where is myelin found? Myelin sheath. What is needed for this

Bad habits, especially alcohol and smoking, cause regular irritation of the cells of the nervous system. Carcinogens accumulate in soft tissues, vasoconstriction occurs, which complicates and accelerates pathogenic processes. Giving up bad habits will preserve your immunity and reduce the risk of disease by 2 times.

Be sure to perform physical therapy for at least 30 minutes a day, as well as follow a diet. Foods rich in omega acids reduce symptoms of the disease.

Is it possible to return to a full life?

Despite the dangers of the disease, many people can live full lives after multiple sclerosis and live quite a long time. To do this, you should lead an active lifestyle, attend sporting events, get a good night's sleep, eat healthy foods, and not overwork yourself.

Important! You should definitely visit your doctor and follow his recommendations.

Myelin

What's happened?

Myelin is the name given to the substance that forms the pulpy sheath, which is responsible for the electrical insulation of nerve fibers, as well as for the speed of transmission of electrical impulses. In simple words, this is the main component in the functioning of the human nervous system.

Can damaged nerves be returned to normal?

Diseases that are associated with destruction of the myelin sheath are treated. However, the process is complex. Myelin restoration is aimed at relieving symptoms and further stopping destruction. The earlier the diagnosis is made, the easier it will be to restore damaged nerves.

How to apply for disability with such a disease, read the article.

How to restore the myelin sheath in multiple sclerosis?

How to restore the myelin sheath? Modern treatment (therapy) makes it possible to do this, but there is no guarantee that the new myelin sheath will function no worse than the previous one.

There is a risk that the disease may become chronic, with symptoms persisting. However, even slight remyelination can stop the progression of the disease and partially restore some functions. Myelin regeneration is carried out using modern medications, the cost of which is quite high.

Treatment

The foci of multiple sclerosis can be the pyramidal system of the brain, as well as the brainstem, cerebellum, optic, and spinal systems. May be violated

The myelin sheath of nerves consists of 70-75% lipids and 25-30% proteins. Its cells also contain lecithin, a representative of phospholipids, whose role is very important: it takes part in many biochemical processes, improves the body's resistance to toxins, and reduces cholesterol levels.

Consumption of products containing lecithin is a good prevention and one of the ways to treat diseases associated with disorders of the nervous system. This substance is found in many cereals, soybeans, fish, egg yolks, and brewer's yeast. Lecithin is also contained in: liver, olives, chocolate, raisins, seeds, nuts, caviar, dairy and fermented milk products. An additional source of this substance can be biologically active food additives.

You can restore the myelin sheath of nerves by including foods containing the amino acid choline in your diet: eggs, legumes, beef, nuts. Omega-3 polyunsaturated fatty acids are very useful. They are found in fatty fish, seafood, seeds, nuts, flaxseed oil and flaxseed. Sources of omega-3 fatty acids can be: fish oil, avocado, walnuts, beans.

The myelin sheath contains vitamins B1 and B12, so it will be useful for the nervous system to include rye bread, whole grain cereals, dairy products, pork, and fresh herbs in the diet. It is very important to consume enough folic acid. Its sources: legumes (peas, beans, lentils), citrus fruits, nuts and seeds, asparagus, celery, broccoli, beets, carrots, pumpkin.

Copper helps restore the myelin sheath of nerves. It contains: sesame seeds, pumpkin seeds, almonds, dark chocolate, cocoa, pork liver, seafood. For a healthy nervous system, it is necessary to include foods containing inositol in your diet: vegetables, nuts, bananas.

It is very important to support the immune system. When there are sources of chronic inflammation or autoimmune diseases in the body, the integrity of the nerves is compromised. In these cases, in addition to the main therapy, it is necessary to introduce food and herbal anti-inflammatory drugs into the menu: green tea, infusions of rosehip, nettle, yarrow, as well as foods rich in vitamins C and D. Vitamin C is found in large quantities in citrus fruits, berries, kiwi, cabbage, sweet peppers, tomatoes, spinach. Sources of vitamin D are eggs, dairy products, butter, seafood, fatty fish, cod liver and other fish.

The diet to restore the myelin sheath of the nerves must contain sufficient amounts of calcium. It is included in many products: milk, cheese, nuts, fish, vegetables, fruits, cereals. For complete absorption of calcium, it is necessary to include magnesium (found in nuts and wholemeal bread) and phosphorus (found in fish) in the diet.

According to Californian experts, the body of every person, regardless of gender, weight and lifestyle, begins to deteriorate at the same time - after 39 years. At the same time, exercise, balanced nutrition, etc. give those who have reached this mark only a feeling of vigor, while upon reaching a “critical” age, cell aging cannot be stopped even by the most careful adherence to the rules of a healthy lifestyle.

The researchers came to this conclusion by calculating that upon reaching the age of 39, the human body stops producing myelin. This chemical compound envelops nerve cells in the brain, providing them with protection from external factors, and is also responsible for the general condition of blood vessels, muscles and skeleton.

« With a lack of myelin, unprotected cells die, resulting in a gradual decline in mental abilities and impaired musculoskeletal functions, that is, the irreversible aging process begins ", note the teaching. Damage to the myelin sheath can lead to numerous injuries, multiple sclerosis and even heart failure, American experts say. True, many of their colleagues working on the same issues do not think so. On the contrary, they are convinced that the theory of the Californian researchers requires careful refinement, since it contradicts the results of earlier studies, which say that the aging process cannot be tied to a specific age.

Neuron and its myelin sheath

However, there are natural ways to restore myelin in the body. The myelin sheath helps nerves transmit signals. If it is damaged, memory problems arise, and a person often develops specific movements and functional impairments. Certain autoimmune diseases and external chemical factors, such as pesticides in food, can damage the myelin sheath. But there are a number of ways, including vitamins and foods, that will help regenerate this covering of nerves: you will need specific minerals and fats, preferably obtained through a nutritious diet. This is even more necessary if you suffer from a disease like multiple sclerosis: usually the body is able to repair damaged myelin sheath with some help from you, but if sclerosis has manifested itself, treatment can become very difficult. So, here are the remedies that will help support the restoration and regeneration of the myelin sheath, as well as prevent sclerosis.

You will need:
- folic acid;
- vitamin B12;
- essential fatty acids;
- vitamin C;
- vitamin D;
- green tea;
- martinia;
- white willow;
- boswellia;
- olive oil;
- fish;
- nuts;
- cocoa;
- avocado;
- whole grains;
- legumes;
- spinach.

1. Supplement your diet with folic acid and vitamin B12.. The body requires these two substances to protect the nervous system and properly repair myelin sheaths. In a study published in the Russian medical journal Vrachebnoye Delo in the 1990s, scientists found that patients suffering from multiple sclerosis who were treated with folic acid showed significant improvement in symptoms and in myelin repair. Both folic acid and B12 can both help prevent the breakdown and regenerate damage to myelin.

2. Reduce inflammation in the body to protect myelin sheaths from damage. Anti-inflammatory therapy is currently the mainstay of treatment for multiple sclerosis, and in addition to taking prescribed medications, patients can also try dietary and herbal anti-inflammatory agents. Natural remedies include essential fatty acids, vitamin C, vitamin D, green tea, martinia, white willow and boswellia.

3. Consume essential fatty acids daily. The myelin sheath is primarily composed of an essential fatty acid: oleic acid, an omega-6 found in fish, olives, chicken, nuts and seeds. Plus, eating deep sea fish will provide you with a good amount of omega-3 acids: to improve mood, learning, memory and overall brain health. Omega-3 fatty acids reduce inflammation in the body and help protect myelin sheaths. Fatty acids can also be found in flaxseed, fish oil, salmon, avocados, walnuts and beans.

4. Support your immune system. Inflammation, which causes damage to myelin sheaths, is caused by immune cells and autoimmune diseases in the body. Nutrients that will help your immune system include: vitamin C, zinc, vitamin A, vitamin D, and vitamin B complex. In a 2006 study published in The Journal of the American Medical Association, vitamin D has been cited as significantly helping to reduce the risk of demyelination and manifestations of multiple sclerosis.

5. Eat foods high in choline (vitamin D) and inositol (inositol; B8). These amino acids are critical for the restoration of myelin sheaths. You can find choline in eggs, beef, beans and some nuts. It helps prevent fat deposits. Inositol supports nervous system health by helping to create serotonin. Nuts, vegetables and bananas contain inositol. The two amino acids combine to produce lecithin, which reduces “bad” fats in the bloodstream. Well, cholesterol and similar fats are known for their ability to interfere with the restoration of myelin sheaths.

6. Eat foods rich in B vitamins. Vitamin B-1, also called thiamine, and B-12 are physical components of the myelin sheath. We look for B-1 in rice, spinach, and pork. Vitamin B-5 can be found in yogurt and tuna. Whole grains and dairy products are rich in all B vitamins, and they can also be found in whole grain bread. These nutrients enhance metabolism, which burns fat in the body, and they also transport oxygen.

7. You also need food containing copper. Lipids can only be created using copper-dependent enzymes. Without this help, other nutrients won't be able to do their job. Copper is found in lentils, almonds, pumpkin seeds, sesame seeds and semi-sweet chocolate. Liver and seafood may also contain copper in lower doses. Dried herbs like oregano and thyme are an easy way to add this mineral to your diet.

The terminal branches of axons in different neurons have a variety of shapes in accordance with the nature of their contacts with the bodies and dendritic branches of other neurons. Axon segments passing through the gray matter give off branches - lateral and recurrent collaterals, also to establish contacts with nearby neurons. The existence of nerve cells lacking axons is controversial. Such axonless elements included, for example, amacrine cells of the retina. Currently, there is reason to consider the processes of these cells as branches not of dendrites, but of the axon.

The extremely rare neurons of the horizontal molecular layer of the cerebral cortex are Cajal-Retzius cells, the peculiarity of which is that those heading to the periphery have been transformed into axons.

Neuron nucleus, cytoplasm, Nissl substance, neurofibrils, mitochondria and other inclusions

Core differs in relatively large sizes, round or oval shape. The volumetric ratio between the nucleus and the cytoplasm of a cell varies significantly in different formations. Small cells usually have a relatively larger nucleus. The nucleus of a nerve cell contains nuclear sap (karyoplasm), in which granules containing ribonucleoprotein (chromatin) are detected using various histological and histochemical methods. The core shell is relatively dense and under an electron microscope is revealed in the form of a double membrane with irregularly located pores.

The structure of the nerve fiber. Myelin sheath

The axons of neurons form nerve fibers. Each fiber consists of an axial cylinder (axon), inside of which there is axoplasm with neurofibrils, mitochondria and synaptic vesicles.

Depending on the structure of the sheaths enveloping the axons, nerve fibers are divided into: nonmyelinated (pulpless) And myelin (pulp).

1. Unmyelinated fiber

Unmyelinated fiber consists of 7-12 thin axons that pass inside a cord formed by a chain of neuroglial cells.

Unmyelinated fibers have postganglionic nerve fibers that are part of the autonomic nervous system.

2. Myelin fiber

Myelin fiber consists of a single axon, which is enveloped myelin sheath and is surrounded by glial cells.

Myelin sheath formed by the plasma membrane of a Schwann or oligodendroglial cell, which is folded in half and wrapped repeatedly around the axon. Along the length of the axon, the myelin sheath forms short sheaths - internodes, between which there are unmyelized areas - Ranvier interceptions.

Myelinated fiber is more perfect than non-myelinated fiber, because it has a higher speed of nerve impulse transmission.

Myelin fibers have the conduction system of the somatic nervous system, preganglionic fibers of the autonomic nervous system.

Molecular organization of the myelin sheath (according to H. Hiden)

1-axon; 2-myelin; 3-axis fiber; 4-protein (outer layers); 5-lipids; 6-protein (inner layer); 7-cholesterol; 8-cerebroside; 9- sphingomyelin; 10-phosphatidylserine.

Chemical composition of myelin

Myelin contains a lot of lipids and little cytoplasm and proteins. On a dry weight basis, the myelin sheath membrane contains 70% lipids (which in total constitutes about 65% of all lipids in the brain) and 30% proteins. 90% of all myelin lipids are cholesterol, phospholipids and cerebrosides. Myelin contains some gangliosides.

The protein composition of myelin in the peripheral and central nervous systems is different. CNS myelin contains three proteins:

Proteolipid, makes up 35–50% of the total protein content in myelin, has a molecular weight of 25 kDa, soluble in organic solvents;

Basic protein A 1 , makes up 30% of the total protein content in myelin, has a molecular weight of 18 kDa, soluble in weak acids;

Wolfgram proteins - several acidic proteins of large mass, soluble in organic solvents, the function of which is unknown. They make up 20% of the total protein content in myelin.

In PNS myelin, proteolipid is absent, the main protein is present proteins A 1 (A little), R 0 And R 2 .

Enzymatic activity has been detected in myelin:

cholesterol esterase;

phosphodiesterase, which hydrolyzes cAMP;

protein kinase A, which phosphorylates the main protein;

sphingomyelinase;

carbonic anhydrase.

Due to its structure, myelin has higher stability (resistance to degradation) than other plasma membranes.

METABOLISM AND ENERGY IN NERVOUS TISSUE

Energy metabolism of nervous tissue

The brain is characterized by a high intensity of energy metabolism with a predominance of aerobic processes. Weighing 1400g (2% of body weight), it receives about 20% of the blood ejected by the heart and approximately 30% of the total oxygen in the arterial blood.

Maximum energy metabolism in the brain is observed during the period of completion of myelination and completion of differentiation processes in children aged 4 years. At the same time, rapidly growing nervous tissue consumes about 50% of all oxygen entering the body.

The maximum breathing rate was found in the cerebral cortex, the minimum - in the spinal cord and peripheral nerves. Neurons are characterized by aerobic metabolism, while the metabolism of neuroglia is also adapted to anaerobic conditions. The respiration rate of gray matter is 4 times higher than that of white matter.

Unlike other organs, the brain has virtually no oxygen reserves. The brain's reserve oxygen is consumed within 10-12 seconds, which explains the high sensitivity of the nervous system to hypoxia.

The main energy substrate of nervous tissue is glucose, the oxidation of which is provided by its energy by 85-90%. Nervous tissue consumes up to 70% of free glucose released from the liver into the arterial blood. Under physiological conditions, 85-90% of glucose is metabolized aerobically, and 10-15% anaerobically.

Neurons and glial cells can use as additional energy substrates amino acids , primarily glutamate and aspartate.

In extreme conditions, nervous tissue switches to ketone bodies(up to 50% of total energy).

In the early postnatal period, the brain also oxidizes free fatty acids and ketone bodies .

The resulting energy is spent first:

to create membrane potential , which is used to conduct nerve impulses and active transport;

for the functioning of the cytoskeleton , providing axonal transport, release of neurotransmitters, spatial orientation of the structural units of the neuron;

for the synthesis of new substances , primarily neurotransmitters, neuropeptides, as well as nucleic acids, proteins, lipids;

for ammonia neutralization .

Metabolism of carbohydrates in nervous tissue

Nervous tissue is characterized by high carbohydrate metabolism, in which glucose catabolism predominates. Since nerve tissue insulin-independent , with high activity hexokinase (has a low Michaelis Menton constant) and low glucose concentration, glucose flows from the blood into the nervous tissue constantly, even if there is little glucose in the blood and no insulin.

The activity of PFS in nervous tissue is low. NADPH 2 is used in the synthesis of neurotransmitters, amino acids, lipids, glycolipids, nucleic acid components and for the functioning of the antioxidant system.

High activity of PFS is observed in children during the period of myelination and with brain injuries.

Metabolism of proteins and amino acids in nervous tissue

Nervous tissue is characterized by a high metabolism of amino acids and proteins.

The rate of protein synthesis and breakdown in different parts of the brain is not the same. The proteins of the gray matter of the cerebral hemispheres and the proteins of the cerebellum are characterized by a high rate of renewal, which is associated with the synthesis of mediators, biologically active substances, and specific proteins. White matter, rich in conductive structures, is renewed especially slowly.

Amino acids in nerve tissue are used as:

source of "raw materials" for the synthesis of proteins, peptides, some lipids, a number of hormones, vitamins, biogenic amines, etc. The synthesis of biologically active substances predominates in the gray matter, and the myelin sheath proteins predominate in the white matter.

neurotransmitters and neuromodulators. Amino acids and their derivatives are involved in synaptic transmission (glu), in the implementation of interneuronal connections .

Energy source . Nervous tissue oxidizes amino acids of the glutamine group and amino acids with a branched side chain (leucine, isoleucine, valine) into the TCA cycle.

To remove nitrogen . When the nervous system is excited, the formation of ammonia increases (primarily due to the deamination of AMP), which binds to glutamic acid to form glutamine. The ATP-consuming reaction is catalyzed by glutamine synthetase.

Amino acids of the glutamine group have the most active metabolism in nervous tissue.

N -acetylaspartic acid (AcA) is part of the intracellular anion pool and a reservoir of acetyl groups. The acetyl groups of exogenous AcA serve as a carbon source for fatty acid synthesis in the developing brain.

Aromatic amino acids are of particular importance as precursors of catecholamines and serotonin.

Methionine is a source of methyl groups and is 80% used for protein synthesis.

Cystathionine important for the synthesis of sulfitides and sulfatilated mucopolysaccharides.

Nitrogen exchange in nervous tissue

The direct source of ammonia in the brain is indirect deamination of amino acids with the participation of glutamate dehydrogenase, as well as deamination with the participation of the AMP-IMP cycle.

The neutralization of toxic ammonia in nervous tissue occurs with the participation of α-ketoglutarate and glutamate.

Lipid metabolism of nervous tissue

A peculiarity of lipid metabolism in the brain is that they are not used as energy material, but are mainly used for construction needs. Lipid metabolism is generally low and differs in white and gray matter.

In neurons of the gray matter, phosphotidylcholines and especially phosphotidylinositol, which is a precursor of the intracellular messenger ITP, are most intensively renewed from phosphoglycerides.

Lipid metabolism in myelin sheaths proceeds slowly; cholesterol, cerebrosides and sphingomyelins are renewed very slowly. In newborns, cholesterol is synthesized in the nervous tissue itself; in adults, this synthesis decreases sharply, until it stops completely.