View source for Gamma-Aminobutyric acid

==Introduction==
Gamma-Aminobutyric acid (GABA) is a naturally occurring [[Amino acid|amino acid]] that works as a neurotransmitter in your brain. Neurotransmitters function as chemical messengers. GABA is considered an inhibitory neurotransmitter because it blocks, or inhibits, certain brain signals and decreases activity in your [[Nervous system|nervous system]].

==Structure and Properties==
GABA is a simple four-carbon structure. It is a non-proteinogenic amino acid, meaning it is not used in the synthesis of proteins. It is the chief inhibitory neurotransmitter in the mammalian central nervous system. It plays a role in regulating neuronal excitability throughout the nervous system. In humans, GABA is also directly responsible for the regulation of muscle tone.

[[Image:Detail-46069.jpg|thumb|center|A close-up view of the molecular structure of Gamma-Aminobutyric acid.|class=only_on_mobile]]
[[Image:Detail-46070.jpg|thumb|center|A close-up view of the molecular structure of Gamma-Aminobutyric acid.|class=only_on_desktop]]

==Biosynthesis==
GABA is synthesized in the brain from its precursor, glutamate, through the action of the enzyme glutamic acid decarboxylase (GAD), with [[Pyridoxal phosphate|pyridoxal phosphate]] as a cofactor. This process converts glutamate (the principal excitatory neurotransmitter) into GABA (the principal inhibitory neurotransmitter).

==Function==
GABA's primary function is to reduce neuronal excitability in the nervous system. It achieves this by binding to specific receptors in the brain which produces a sedative effect. This can help with feelings of anxiety, stress, and fear. It may also help to prevent seizures. As such, GABA is a critical component in a number of pharmaceutical drugs used to treat these conditions.

==Pharmacology==
GABA receptors are a class of receptors that respond to the neurotransmitter gamma-aminobutyric acid. They are the GABA_A, GABA_B, and GABA_C classes. GABA_A receptors are ligand-gated ion channels; whereas GABA_B receptors are G protein-coupled receptors. These receptors are the targets of a variety of pharmaceutical drugs, including benzodiazepines, barbiturates, and alcohol.

==Clinical Significance==
GABA is a significant neurotransmitter that is implicated in a variety of clinical conditions. Deficiencies in GABA are linked to disorders such as epilepsy, and there is evidence that suggests GABA could play a role in mood disorders like depression and anxiety. Additionally, GABA is a major factor in schizophrenia and Huntington's disease.

==See Also==
* [[Neurotransmitter]]
* [[Amino acid]]
* [[Nervous system]]
* [[Pyridoxal phosphate]]

[[Category:Neurotransmitters]]
[[Category:Amino acids]]
[[Category:Neurochemistry]]