Gamma-Amino Butyric Acid, GABA

"γ-Aminobutyric acid ( /ˈɡæmə əˈmiːnoʊbjuːˈtɪrɨk ˈæsɨd/ gam-ə ə-mee-noh-bew-tirr-ik; or GABA /ˈɡæbə/) is the chief inhibitory neurotransmitter in themammalian 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."

"Although chemically it is an amino acid, GABA is rarely referred to as such in the scientific or medical communities, because the term "amino acid," used without a qualifier, conventionally refers to the alpha amino acids, which GABA is not, nor is it ever incorporated into a protein."

"In spastic diplegia in humans, GABA absorption becomes impaired by nerves damaged from the condition's upper motor neuron lesion, which leads tohypertonia of the muscles signaled by those nerves that can no longer absorb GABA."