Excitatory amino acid neurotoxicity.

The excitatory potency of the acidic amino acids glutamate and aspartate in various regions of the central nervous system (CNS) has been recognized since the 1960 s.1,2 Nevertheless, the earlier findings that these amino acids are (1) constituents of intermediary metabolism and are (2) located in the brain ubiquitously in high concentrations rendered them unlikely candidates as neurotransmitters. These findings fueled a sustained debate about their physiological role as neurotransmitters in the 1970s. Today, L-glutamate is accepted as the predominant fast excitatory neurotransmitter in the vertebrate brain.