Excitatory Amino Acid Receptors

The dicarboxylic amino acids L-glutamate (Glu) and L -aspartate (Asp) are found throughout the mammalian central nervous system. Although it was initially believed that these amino acids participated solely in the metabolic activities of the brain, evidence that Glu and Asp are excitatory neurotransmitters is now substantial (reviewed in Curtis et al., 1972 ; Davies et al., 1979 ; Davies et al., 1980 ; Coyle, 1980 ; Watkins and Evans, 1981 ). Beyond a fundamental role as chemical mediators of synaptic transmission, there is an increasing suspicion that alterations in the neurochemistry of excitatory amino acids are involved in the etiology or symptomatic presentation of several neuropsychiatric and neurodegenerative disorders (Olney and Gubareff, 1978 ; Nadler, 1981 ; Coyle, 1982a ).