GABA (gamma-aminobutyric acid) is an inhibitory neurotransmitter, which functions to slow down or weaken neuron signals. This is unlike other neurotransmitters (adrenaline, nor-adrenaline, serotonin, dopamine, and glutamate) which all have an excitatory function (i.e., they are responsible for stimulating neuron firing). Gamma-aminobutyric acid occurs naturally within the brain where it is vital in regulating brain activity, there is also evidence to support its important role in regulating muscle tone. GABA is technically an amino acid, even though it is not part of any protein either in the human body or in food. Very small amounts of it can be obtained from food, however, the majority of it is synthesized from glutamate in the body.
Due to its inhibitory function, it plays a vital plays role in anxiety. In this situation, when nerve signals fire too quickly and possess anxiety-inducing signals, GABA is activated and acts in order to slow the signals down and therefore reducing overwhelming feelings of anxiety. However, in individuals with anxiety disorders (e.g., post-traumatic stress, panic disorder, and generalized anxiety), gamma-aminobutyric acid does not function as it should and this results in elevated levels of anxiety. There are many remedies and medications which are currently being used for anxiety, benzodiazepines are able to reduce anxiety through the way they interact with GABA receptors. Coffee can inhibit GABA and therefore make an individual more buzzed up or anxious.