Let's learn about the 'wire covering' that transmits electrical messages in our body at high speed - the Myelin Sheath.

Have you ever wondered how it happens so quickly when you want to move your hand? Or how we pull our hand back after touching something hot? All of this happens because of the incredibly fast electrical messages that travel from our brain to other parts of our body, and from parts of our body back to our brain. So, our nerve cells have a very special 'protective coating' around them that helps these messages travel so quickly and without any problems. That's what we call the Myelin Sheath . Today we're going to talk about this amazing myelin sheath.

Simply put, what is this myelin sheath?

Imagine that the electricity in our house is a single wire. That wire has a plastic cover around it. Why is that? One is that it provides protection for the wire. Another is that it helps the electricity to travel quickly to where it needs to go, without leaking to other places.

The same is true of the myelin sheath. This is a special coating made of lipids and proteins . This myelin sheath is wrapped around the longest part of our neurons, the main 'wire' that carries messages. This not only protects the nerve cell, but also helps the electrical signals travel very quickly and efficiently.

Let's first understand a little about the parts of a nerve cell.

To understand this, let's compare a neuron to a small tree. Then you can remember this very easily.

1. Cell body (Soma): This is like the root system of a tree. Just as the roots of a tree absorb nutrients from the soil, the dendrites , which are the root-like parts of the cell body, 'absorb' chemical messages from other nearby nerve cells. These chemical messages are then converted into electrical signals. The nucleus of the cell is also located in this part.

2. Axon: This is the long part that looks like the trunk of a tree. Just as the nutrients from the roots of a tree travel up the trunk, the electrical signals generated in the cell body travel along this axon.

3. Axon Terminal: This is like the buds at the ends of the branches of a tree. Like leaves and flowers coming out of those buds, the axon terminal 'releases' that electrical signal to the next nerve cell.

This is how messages jump from one nerve cell to another. It's like a relay race. This is how messages travel from our brain and spinal cord throughout our bodies. The muscles in your arms contract, you breathe, your heart beats, all of this is controlled by this amazing process of communication.

What are the main functions of the myelin sheath?

As we discussed earlier, the myelin sheath has three main functions.

• Providing protection: Like the plastic sheath around an electrical wire, this coating of fats and proteins provides good protection for the axon of the nerve cell.
• Speeding up: This is the most important thing. The myelin sheath allows electrical signals to travel extremely quickly and efficiently from one nerve cell to another.
• Maintaining signal strength: As the electrical signal travels along the axon, it can weaken. However, the myelin sheath helps to maintain the strength of the signal without reducing it.

What happens if the myelin sheath is damaged?

There are about 100 billion nerve cells in our body that are constantly firing. All our actions are controlled by this exchange of messages. So imagine what would happen if the myelin sheath around these nerve cells were damaged. Then those fast electrical signals would start to travel slowly, or stop altogether .

The main reason for this damage is that our own immune system mistakenly thinks that the myelin sheath is something harmful to the body from the outside. Then, our immune cells start attacking the myelin sheath. This attack destroys the myelin. We call this process demyelination . Over time, even the cells that make myelin are destroyed. In this way, we develop different symptoms depending on where the myelin sheath is damaged.

What diseases damage the myelin sheath?

There are many diseases that damage the myelin sheath. You may have heard of some of them. Let's divide these diseases into two categories: those that affect our central nervous system (CNS), which is the brain and spinal cord, and those that affect the peripheral nervous system (PNS), which is the rest of the body's nerves.

Can myelin be damaged for other reasons?

Yes. In addition to the diseases mentioned above, the myelin sheath can be damaged due to several other reasons.

• Stroke: Caused by impaired blood flow to the brain.
• Infections and metabolic disorders: Due to some infections and problems with chemical processes in the body.
• Poisons: Ingestion of certain toxins.
• Vitamin B12 deficiency: This vitamin is essential for the production of myelin.
• Some types of medications: For example, medications such as ethambutol.
• Excessive alcohol consumption: Long-term alcohol use is also harmful to myelin.

Additionally, in very rare, hereditary conditions such as Tay-Sachs disease, the myelin sheath may not form properly.

Can damage to myelin be reversed?

This is the most important question for everyone. The good news is, yes, it is possible to repair damaged myelin . This repair can occur in both our central and peripheral nervous systems.

The most important thing for this is to control the underlying factors that cause myelin destruction. For example, it is very important to give drugs such as steroids to control inflammation caused by the activity of the immune system, and to use other treatments that control the immune system (immune suppression/modulation treatment).

Scientists are currently conducting a large amount of research into how to repair damaged myelin. Although there is still no approved drug to repair myelin, research results are showing great promise for the future.

• Some research has shown that the allergy medication ``clemastine`` has the ability to repair myelin.
• Research is also underway into whether myelin can be regenerated using stem cells.
• Research is also underway into drugs that protect the nervous system from further damage.

So, this research shows that there is a great potential for better treatments for patients with myelin damage in the future.

Myelin, nervous system, multiple sclerosis, nerve cells, demyelination, neurological diseases, body function