What are GABA receptors

The Gamma (y) aminobutyric acid (short: GABA) is the most important inhibitory neurotransmitter in the central nervous system of mammals. In contrast to excitatory neurotransmitters such as glutamate, adrenaline or dopamine, GABA reduces the excitability of nerve cells.
As soon as a GABA molecule binds in a specific GABA receptor, ion channels open which are responsible for chloride ions (Cl-) are permeable. As a result, the influx of negatively charged ions leads to hyperpolarization of the postsynaptic membrane (IPSP) and thus to inhibition of excitation. This principle applies at least to GABAaReceptors. Depending on the type of GABA receptor, there are differences in how the inhibition works.

GABA is obtained in the human organism from the non-essential amino acid glutamic acid. Glutamic acid (C.5H9NO4) is converted by glutamate decarboxylase in both the brain and the pancreas to GABA (C.4H9NO2) decarboxylated. During this process, the enzyme glutamate decarboxylase splits a carbon dioxide molecule (CO2) from the amino acid.

In the brain, GABA is the most common neurotransmitter with a share of about 1/3. It is therefore not surprising that sleep is essentially controlled by the inhibitory function of the GABAergic neurons. Medicines such as narcotics or benzodiazepines to induce sleep or to reduce anxiety also bind to the y-aminobutyric acid receptors and thus inhibit arousal.
In the pancreas, the other place in the body where GABA transmitters and receptors are found in large quantities, γ-aminobutyric acid helps control blood sugar levels. There, GABA controls the inhibition of the secretion of the hormone glucagon, which is responsible for the rise in blood sugar levels.