Johnston et al (1980) Potentiation of L-glutamate and L-aspartate excitation of cat spinal neurones by the stereoisomers of threo-3-hydroxyaspartate. J.Neurochem. 34 241. McBean and Roberts (1985) Neurotoxicity of L-glutamate and DL-threo-3-hydroxyaspartate in the rat striatum. J.Neurochem. 44 247. Nakamura et al (1993) (2S,3S,4R)-2-(carboxycyclopropyl)glycine, a potent and competitive inhibitor of both glial and neuronal uptake of glutamate. Neuropharmacolgy 32 833.