Neurotransmitters – Substances that improve the functioning of the nervous system

Neurotransmitters ? The nervous system is an extremely complex mechanism that controls the actions and functions in our bodies, from physical movements to every thought and mental activity. The daily life of modern man is associated with increased stress on the nervous system, which is associated with sleep deprivation, high stress, stressful work process, daily exposure and use of stimulants or food supplements. Apart from the fact that negative influences can lead to a decrease in some neurotransmitters in the body, they often lead to chronic diseases of the nervous system.

We should ask ourselves: would taking neurotransmitters benefit the body? Imagine a better mood, better quality sleep, faster thinking. Could these substances be the most faithful helper of the nervous system?

What are neurotransmitters and how do they work?

The nervous system is an integral part of the body of every animal, including man. Its main function is to coordinate actions and transmit signals between different parts of the body. At the cellular level, the nervous system functions through nerve cells or neurons that send signals in the form of electrochemical waves through nerve fibers (axons) that cause synapses to secrete chemicals called neurotransmitters.

The first neurotransmitter discovered was acetylcholine and was identified as such by Dr. Otto Leewi, who later received the Nobel Prize for his work. New discoveries followed in the mid-20th century, when norepinephrine, dopamine, serotonin and gaba were identified. The popularity of neurotransmitters as dietary supplements revealed their potential in the late 90’s, and nowadays some of them or their powerful precursors can be found on the stands of specialized sites and stores.

A neurotransmitter is a chemical that acts as a “messenger” that sends, stimulates and regulates signals between neurons and other cells in the body. It is released from the synapses, reaching the receptors on neurons or other cells, attaching to the receptors in the chain, and is eventually absorbed by the neurons. It is the neurotransmitters that are responsible for transmitting information to the human body.

Neurotransmitters are divided into two main types, depending on their effect on the nervous system. They can be excitatory, causing action in nerve cells, or be depressing, causing the exact opposite – inaction of nerve cells. In fact, the direct effect of neurotransmitters is limited to the activation of one or more receptors, and the induction or suppression of action depends on the nature of the receptor itself. Some receptors have an entirely excitatory effect (glutamate), while others have an inhibitory effect (GABA). For others, such as acetylcholine, it is characteristic to have both types of effects.

Types of neurotransmitters

Depending on their structure, neurotransmitters are divided into:

• Amino acids – Gamma-aminobutyric acid (GABA), glycine, glutamate, aspartate;
• Biogenic amines or monoamines (aromatic amino acids) – dopamine, octopamine, tyramine, norepinephrine, epinephrine, norepinephrine, melatonin, histamine and serotonin;
• Peptides – somatostatin, substance P and endorphins;
• Independent neurotransmitters – acetylcholine, nitric oxide, adenosine and others.

Depending on their effect on the nervous system, neurotransmitters are divided into excitatory and suppressive. Stimulants include glutamate, aspartate, serotonin, dopamine, norepinephrine, epinephrine, norepinephrine and histamine. GABA and glycine have a suppressive effect, and acetylcholine can have both an excitatory and a suppressive effect.

Neurotransmitter precursors

Most neurotransmitters are not found in food and therefore do not have a direct natural source. For this purpose, neurotransmitters are synthesized from their precursors, which have food or herbs as sources. One of the strongest precursors of neurotransmitters is l-dopa, a chemical that has some animals and plants as natural sources. Animals, including humans, synthesize L-Dopa from the amino acid L-tyrosine.

L-Dopa is found in large amounts in some herbs such as couch (Mucuna pruriens) and beans (Vicia faba). L-Dopa is a potent precursor of the neurotransmitters dopamine, norepinephrine and epinephrine. The amino acids tyrosine and phenylalanine also have precursor properties of dopamine, otcopamine, tyramine, norepinephrine and epinephrine, but metabolic processes also require the involvement of some important coenzymes, such as vitamin B-6 and other mediators.

Proven precursors of the neurotransmitter serotonin are the amino acid L-tryptophan, which requires vitamin C to convert. Another powerful precursor of serotonin is the amino acid 5-hydroxytryptophan (5-HTP), which is derived from the plant Griffonia simplicifol. In vivo studies have shown that the amino acid glutamine successfully increases GABA levels, but due to conflicting results regarding the effectiveness of glutamine when taken orally, it is difficult to prove the potential benefits of glutamine as a precursor.

Acetyl carnitine, huperzine A and alpha-glycylphosphorylcholine are proven precursors of the neurotransmitter acetylcholine, while the clinical results for dimethylaminoethanol (DMAE) are still controversial.

The specific action of some neurotransmitters

Individual neurotransmitters have different effects because they affect entire independent neuromodulatory systems. The main neurotransmitter systems are cholinergic, norepinephrine, serotonin and dopamine. The action of other neurotransmitters such as GABA, glutamate, glycine and aspartate is associated with the functioning of the central nervous system and the brain.

• The norepinephrine (also called norepinephrine) system binds to the neurotransmitter norepinephrine, which is secreted by sympathetic neurons by affecting the heart. The norepinephrine system is also called stress and controls actions such as animal survival instincts (“fight or flight”), increases heart rate, secretes glucose from muscle stores and oxygen stores in the brain;
• The dopamine system is related to its effects on the sympathetic nervous system and the part of the brain responsible for learning. Dopamine does not directly affect the central nervous system because it cannot cross the brain barrier. On the other hand, its precursors can and are more effective in affecting the brain. Dopamine stimulates behaviors such as cognitive processes, voluntary movements, punishment and reward, inhibits prolactin synthesis, stimulates sleep, dreams, mood, attention, memory and learning;
• The serotonin system is mainly associated with the peripheral nervous system, as an extremely small percentage of serotonin receptors are contained in the central nervous system. Serotonin plays an important role in mood, happiness, satisfaction, quality sleep, body temperature, suppresses pain and enhances introversion (turning the individual to himself);
• The cholinergic system plays a major role in both the central nervous system and the peripheral. The neurotransmitter acetylcholine is responsible for muscle and motor control, short-term memory, post-sleep concentration, sleep quality, reaction time and decision making;

• Other neurotransmitters have an independent role in neuromodulation. Glutamate functions in the central nervous system and has a completely over-excitatory effect, as its high amounts can stimulate the brain and cause cell death (the same negative effect applies to caffeine – ed. Note). Its normal amounts stimulate memory and learning. GABA, in turn, is the major neurotransmitter in mammalian central nervous systems, involved in the regulation of muscle movements and brain development. Aspartate also stimulates n-methyl-d-aspartate receptors, but not to the same extent as glutamate.