Gamma-aminobutyric acid (GABA) is the chief inhibitory neurotransmitter in the mammalian central nervous system. It plays an important role in regulating neuronal excitability throughout the nervous system, and disrupted GABAergic signaling has been implicated in numerous and varied neurological and psychiatric pathologies including movement and anxiety disorders, epilepsy, schizophrenia, and addiction. GABA is also responsible for the regulation of muscle tone.