Types of neurotransmitters: functions and classification
The neurotransmitters they are chemical substances created by the body that transmit signals (that is, information) from one neuron to the next through contact points called synapse. When this happens, the chemical substance is released by the vesicles of the pre-synaptic neuron, crosses the synaptic space and acts by changing the action potential in the post-synaptic neuron.
There are different neurotransmitters, each with different functions . In fact, the study of this class of substances is fundamental to understanding how the human mind works. In this article, we will review some of the most significant neurotransmitters.
- Related article: "Types of neurons: characteristics and functions"
Main neurotransmitters and their functions
The list of known neurotransmitters has been increasing since the 1980s, and at present more than 60 have been counted .
This is not strange, considering the complexity and versatility of the human brain. It produces all kinds of mental processes, from the management of emotions to the planning and creation of strategies, through the realization of involuntary movements and the use of language.
All this variety of tasks he has behind him many neurons coordinating with each other to make the different parts of the brain function in a coordinated way, and for this it is necessary that they have a mode of communication capable of adapting to many situations.
The use of different types of neurotransmitters allows to regulate in different ways the way in which one or other groups of nerve cells are activated. For example, a certain occasion may require serotonin levels to go down and dopamine levels to rise, and that will have a determined consequence in what happens in our mind. Thus, the existence of the wide variety of neurotransmitters allows the nervous system to have a wide range of behaviors, which is necessary to adapt to a constantly changing environment.
But, What are the most important neurotransmitters in the human body and what functions do they perform? The main neurochemicals are mentioned below.
This neurotransmitter is synthesized from tryptophan, an amino acid that is not manufactured by the body, so it must be provided through the diet. Serotonin (5-HT) It is commonly known as the happiness hormone , because low levels of this substance are associated with depression and obsession.
- Maybe you're interested: "Serotonin: discover the effects of this hormone on your body and mind"
In addition to its relationship with the state of mind, 5-HT performs different functions within the organism, among which stand out: its fundamental role in digestion, the control of body temperature, its influence on sexual desire or its role in the regulation of the sleep-wake cycle.
The excess of serotonin can cause a set of symptoms of different severity.
- If you want to know more, you can visit our article: "Serotonin syndrome: causes, symptoms and treatment"
Dopamine is another of the best known neurotransmitters, because is involved in addictive behaviors and is the cause of pleasurable sensations . However, among its functions we also find the coordination of certain muscular movements, the regulation of memory, the cognitive processes associated with learning and decision making
- To know more: "Dopamine: 7 essential functions of this neurotransmitter"
Have you noticed that after going for a run or practicing physical exercise you feel better, more lively and energetic? Well this is mainly due to endorphins, a natural drug that is released by our body and that produces a feeling of pleasure and euphoria.
Some of its functions are: promote calm, improve mood, reduce pain , delay the aging process or enhance the functions of the immune system.
4. Adrenaline (epinephrine)
Adrenaline is a neurotransmitter that triggers survival mechanisms , because it is associated with situations in which we have to be alert and activated because it allows us to react in situations of stress.
In short, adrenaline fulfills both physiological functions (such as regulating blood pressure or respiratory rhythm and pupil dilation) and psychological functions (keeping us alert and being more sensitive to any stimulus).
- To delve into this chemical, you can read our post: "Adrenaline, the hormone that activates us"
5. Noradrenaline (norepinephrine)
Adrenaline is involved in different functions of the brain and is related to motivation, anger or sexual pleasure. The mismatch of noradrenaline is associated with depression and anxiety.
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Glutamate is the most important excitatory neurotransmitter in the central nervous system . It is especially important for memory and recovery, and is considered the main mediator of sensory, motor, cognitive, emotional information. In a way, it stimulates several mental processes of essential importance.
Research claims that this neurotransmitter is present in 80-90% of the brain's synapses. Excess glutamate is toxic to neurons and is related to diseases such as epilepsy, stroke or amyotrophic lateral disease.
- Related article: Glutamate (neurotransmitter): definition and functions
GABA (gamma-aminobutyric acid) acts as an inhibitory messenger, so it slows down the action of excitatory neurotransmitters . It is widely distributed in cortical neurons, and contributes to motor control, vision, regulates anxiety, among other cortical functions.
On the other hand, this is one of the types of neurotransmitters that do not cross the blood-brain barrier, so it must be synthesized in the brain. Specifically, it is generated from glutamate.
- Learn more about this neurotransmitter by clicking here.
As a curiosity, and This is the first neurotransmitter that was discovered . This happened in 1921 and the discovery took place thanks to Otto Loewi, a German biologist who won the Nobel Prize in 1936. Acetylcholine widely distributed by the synapses of the central nervous system, but also found in the peripheral nervous system.
Some of the most outstanding functions of this neurochemical are: participates in the stimulation of muscles, in the passage from sleep to wakefulness and in the processes of memory and association .
Classification of neurotransmitters
Neurotransmitters can be classified as follows:
- Amines : They are neurotransmitters that derive from different amino acids such as, for example, tryptophan. In this group are: Norepinephrine, epinephrine, dopamine or serotonin.
- Amino acids : Unlike the previous ones (that derive from different amino acids), these are amino acids. For example: Glutamate, GABA, aspartate or glycine.
- Purines : Recent research indicates that purines such as ATP or adenosine also act as chemical messengers.
- Gases : Nitric oxide is the main neurotransmitter of this group.
- Peptides : The peptides are widely distributed throughout the encephalon. For example: endorphins, dynorphins and tachykinins.
- Esters : Acetylcholine is found within this group.
Do not forget that, although each of the types of neurotransmitters can be associated with certain functions in the nervous system (and, therefore, certain effects at a psychological level), it is not about elements with intentions and an objective to follow, so that its repercussions in us are purely circumstantial and depend on the context.
In other words, neurotransmitters have the effects they have because our organism has evolved to make this substance exchange something that helps us survive, by allowing the coordination of different cells and organs of the body .
Therefore, when we consume drugs that emulate the functioning of these neurotransmitters, they often have side effects that may even be the opposite of the expected effect, if they interact abnormally with substances that are already in our nervous system. The balance that remains in the functioning of our brain is something fragile, and neurotransmitters do not learn to adapt their influence in us to meet what is supposed to be "their function"; We must worry about that.
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- Pérez, R. (2017). Pharmacological treatment of depression: news and future directions. Rev. Fac. Med. (Méx.), 60 (5). Mexico City.