GABA (neurotransmitter): What It Is And What Role It Plays In The Brain
He GABA (gamma-aminobutyric acid) is a neurotransmitter widely distributed in the neurons of the cerebral cortex. What does this mean? Well, GABA is a type of substance that is used by the neurons of the nervous system when communicating with each other through spaces (called synaptic spaces) through which they connect with each other.
In this sense, gamma-aminobutyric acid is not very different from the rest of the neurotransmitters: they all have the same basic function, allowing nerve cells to send nerve impulses to each other and send “orders” to other parts of the body. Now, it performs some functions that other neurotransmitters do not do. Its function is to be a inhibitory neurotransmitter , although with nuances. So, let’s see what GABA consists of and what functions it performs in the human body.
As we have seen, GABA is just one of many types of neurotransmitters that act in the brain. This group of substances are molecules that are released by neurons and, at the same time, fit with certain structures located on the surface of neurons, called neuronal receptors.
Definitely, sends chemical messages through the brain and nervous system , such as serotonin or dopamine, among other molecules; It participates in the communication between neurons at the moment in which the electrical currents that run through them reach an end and give rise to the release of neurotransmitters, which travel through the synaptic space until they reach the receiving neuron, being captured by a neuronal receptor. , and give rise to a certain pattern of electrical activity in this second nerve cell.
The role of GABA is to inhibit or reduce neuronal activity, and it plays an important role in behavior, cognition, and the body’s response to stress. Research suggests that GABA helps control fear and anxiety when neurons become overexcited.
On the other hand, low levels of this neurotransmitter are associated with anxiety disorders, sleeping problems, depression and schizophrenia. It has also been found that young neurons are more excitable than old ones, and this is due to the function that GABA exerts on the latter.
GABA contributes to motor control, vision or regulates anxiety, among other cortical functions. There are different drugs that increase GABA levels in the brain and are used to treat epilepsy, Huntington’s disease or to relieve anxiety (for example, benzodiazepines).
It must be taken into account, however, that it is still know little of what are the functions and processes in which GABA intervenes, and therefore it is hasty to assume that its usefulness is simply what I have described. Furthermore, this neurotransmitter intervenes to a greater or lesser extent in other communication dynamics between neurons in which other neurotransmitters have a more relevant role.
The relationship between GABA and fear and anxiety
GABA was discovered in 1950 by Eugene Roberts and J. Awapara, and since then various studies have been carried out to better understand its relationship with anxiety disorders.
In the last decades, Research on GABA and benzodiazepines has been numerous , basically to seek treatments against the pathological alterations of fear and anxiety. These studies have concluded that GABA is involved in these emotions, but it does not seem that its role is other than that of an inhibitory modulator of other neurotransmission systems such as norepinephrine.
In addition, other studies have also provided interesting conclusions regarding how the effect of this neurotransmitter is capable of reducing the effects of stress in individuals. In an experiment published on Journal of Neuroscience It was shown that when individuals perform regular physical exercise, the level of GABA neurons increases in the brain, which affects the ventral hippocampus, a brain region linked to the regulation of stress and anxiety. Another study, this time carried out jointly by Boston University and the University of Utah, found that there is also an increase in this neurotransmitter in yoga practitioners.
To learn more about the psychological benefits of physical exercise and yoga you can read our articles:
How is GABA synthesized?
GABA is synthesized from the decarboxylation of glutamate thanks to the action of the enzyme glutamate decarboxylase (GAD), a process that occurs in GABAergic neurons in the cerebellum, basal ganglia and many areas of the cerebral cortex, also in the spinal cord. . If the synthesis of this neurotransmitter is inhibited, convulsive attacks occur.
GABA receptors
GABA receptors are probably the most numerous in the mammalian nervous system. It is estimated that They are present in at least 30-40% of the nerve cells in the human brain
There are three types of receptors for GABA: GABA-A, GABA-B and GABA-C. The latter is considered a subtype of the GABA-A receptor, and is also called GABA-A rho.
The GABA-A receptor, the best known
The ionotropic GABA-A receptor, which is located on the plasma membrane of the post-synaptic terminal, is the one related to benzodiazepines such as Diazepam (better known as Valium), barbiturates or alcohol. It is the best known receptor and is composed of five polypeptide subunits : α, β, γ, δ, ε, each with different functions.
If you want to know more about this receptor, the following video explains the structure and operation of the GABA-A receptor:
The GABA-B receptor is metabotropic, and is found in the plasma membrane of pre- and post-synaptic terminals. The GABA C receptor, like GABA-A, is ionotropic.
Ionotropic and metabotropic receptors
Ionotropic receptors receive this name because they are coupled to an ion channel, which when the ligand binds to them, the channel opens and an ion enters or leaves through the channel. In the case of the GABA-A receptor, chlorine (Cl-) enters, which produces the inhibitory response. Its effect is fast because you only have to open the channel to produce the action.
In contrast, metabotropic receptors, such as GABA-B, are slower receptors and are coupled to G proteins, which, specifically in the case of this receptor, lead to the activation of Potassium (K+) channels for the depolarization of the cell. .
Other neurotransmitters and their functions
In addition to GABA, in Psychology and Mind We have already talked about other neurotransmitters and their functioning within the brain. Among them serotonin, also known as the happiness hormone, and dopamine, a chemical related to pleasurable behaviors and reinforcement. So don’t miss the following articles:
