ALONE COWBOY :ACETYLCHOLINE
You are probably familiar with the name acetylcholine. It was discovered in heart tissue by Henry Hallett Dale over 100 years ago. Then Otto Loewi showed that it was a neurotransmitter. Both scientists were awarded the Nobel Prize. As acetylcholine is the first neurotransmitter discovered , it has a special place in our hearts.
The places where acetylcholine functions are not limited to brain tissue. Besides neurons, it performs very important tasks in muscles and glands. It takes its name from its chemical structure: ester of acetic acid and choline molecules. If you hear the cholinergic name somewhere, know that acetylcholine is mentioned. For example cholinergic neurons . These neurons communicate by using acetylcholine. It has an important role in the communication between motor neurons and muscles. The secretion of acetylcholine from neurons stimulates the striated muscles and ensures their contraction. Therefore, drugs that can affect the cholinergic system have very dangerous effects. It can also put you in chills of tremor or paralysis.
How is acetylcholine produced and secreted?
The choline acetyltransferase enzyme is key in the production of acetylcholine. Production of acetylcholine continues in certain neurons after the necessary components are provided. This neurotransmitter is not carried back into the cell, such as serotonin or dopamine . It is used and recycled. This task is assumed by the enzyme acetylcholinesterase. If this enzyme does not work, many muscle problems occur. Some toxins can block this enzyme from working, causing paralysis and even stop breathing. The heart muscles may not work and the heartbeat may stop.
So far, we have focused on the vital duties of acetylcholine, but it has many more functions in both the brain and the body. Acetylcholine acts in the central nervous system and the peripheral nervous system. It is found in many areas in the brain, from the basal forebrain to the cerebral cortex and the hippocampus . Acetylcholine also has a role in cognitive functions, as neurons in the frontal region of the brain concentrate on cognitive functions. In the peripheral nervous system, as mentioned above, it affects the muscles and glands. It is one of the staff of the autonomic nervous system, as most muscles in the body can penetrate .
Acetylcholine Receptors
You came home from work in the evening, you are very tired. You want to enter the house and lie down on the sofa right away. When you come to the door of the house, you realize that your key does not fit in the lock. It turns out that you got the keys to the summer house in the morning. Cellular-scale active substances also work according to the key lock principle. No matter how much acetylcholine you have, it won't work if you don't have the proper receptor. There are several types of receptors to which acetylcholine binds. These are basically called muscarinic and nicotinic .
Nicotine, as you know, is a substance in tobacco. Muscarin is also found naturally in Amanita muscaria mushrooms. The names of the receptors are given because these chemicals activate them. Nicotine receptors are ion channels. The binding of acetylcholine to these receptors allows ions such as sodium, potassium and calcium to enter the cell. These receptors are found in both muscles and neurons. Muscarinic receptors affect the intracellular signaling mechanism. It initiates the signal chain, which allows the cell to be stimulated and stopped according to its type.
What are the substances that block acetylcholine?
We briefly talked about the functions of acetylcholine in the brain and body. It plays a role in cognitive functions in the brain, especially in the forebrain. But perhaps its most important task is to stimulate the muscles to contract in the body. If this molecule does not work properly , problems such as stroke and chills occur . Even breathing and cardiac arrest can be seen. The acetylcholine mechanism does not stop easily, but there are some things blocking it. For example, antibiotics such as clindamycin and polymyxin are problematic. Magnesium prevents acetylcholine from working because it inhibits P-type calcium channels. In addition, hypocalcemia, diuretic drugs and Botulinum toxin damage the mechanism.
