GABA (neurotransmitter): what it is and what functions does it perform

The GABA (gamma-aminobutyric acid) is a neurotransmitter widely distributed in 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 it comes to communicate with each other through spaces (called synaptic spaces) by which they connect between they.

Now, GABA is just one of many types of neurotransmitters of the many that act in the brain. That is why it performs some functions that other neurotransmitters do not. Its function is to be a inhibitory neurotransmitter.

GABA, the inhibitory neurotransmitter

GABA is a neurotransmitter (like serotonin or dopamine) and therefore sends chemical messages through the brain and nervous system. In other words, it participates in the communication between neurons.

GABA's role 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, sleep problems, depression Y schizophrenia. It has also been found that young neurons are more excitable than old ones, and this is due to the role 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 calm anxiety (for example, benzodiazepines).

It must be borne in mind, however, that it is still knows little of what are the functions and processes in which GABA intervenes, and therefore it is rash 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 play a more relevant role.

GABA's relationship to 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 extensive, basically to seek treatments against pathological alterations of the afraid and anxiety. These studies have concluded that GABA is involved in these emotions, but it does not appear that its role other than the inhibitory modulator of the other neurotransmission systems such as that of the noradrenaline.

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 physical exercise on a regular basis, the level of GABA neurons increases in the brain, affecting 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 practitioners of yoga.

To learn more about the psychological benefits of physical exercise and yoga, you can read our articles:

• The 10 psychological benefits of practicing physical exercise
• The 6 psychological benefits of yoga
• 10 benefits of yoga for athletes (according to science)

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, the basal ganglia and many areas of the cerebral cortex, also in the spinal cord. If the synthesis of this neurotransmitter is inhibited, seizures occur.

GABA receptors

GABA receptors are probably the most numerous in the mammalian nervous system. It is estimated that are present in at least 30-40% of 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 postsynaptic terminal, is the which is 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 it is found on the plasma membrane of the 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 the channel. In the case of the GABA-A receptor, chlorine (Cl-) enters, which produces the inhibitory response. Its effect is fast because you just 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, they lead to the activation of Potassium channels (K +) 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 how they work within the brain. Among them serotonin, also known as the happiness hormone, and dopamine, a chemical related to pleasant behaviors and reinforcement. So don't miss the following articles:

• Serotonin: discover the effects of this hormone on your body and mind
• Dopamine: 7 essential functions of this neurotransmitter

Bibliographic references:

• Bloom, F. 1994. Psychopharmacology. The fourth generation of progress. Raven Press.