Gamma-aminobutyric acid, commonly known as GABA, is a neurotransmitter in the brain that plays a crucial role in regulating neuronal excitability. It is primarily responsible for inhibiting nerve transmission, which helps to calm the nervous system and reduce feelings of anxiety and stress. GABA is synthesized from glutamate, another neurotransmitter, and is found in various regions of the brain. GABA is often studied for its potential therapeutic effects, particularly in treating conditions like anxiety disorders, epilepsy, and insomnia. Some people also take GABA supplements to promote relaxation and improve sleep quality, although the effectiveness of these supplements can vary.