ABSTRACT

There is no doubt that administration of large amounts of the dicarboxylic amino acids glutamate and aspartate to neonatal rodents produces hypothalamic neuronal necrosis. Although the glutamate-induced lesion has been studied extensively, aspartate is less well studied. The controversy over nonhuman primate data relative to the use of glutamate as a food additive led to studies to determine the threshold plasma concentration of glutamate and aspartate associated with neuronal necrosis in the infant mouse. Neuropathological studies were performed on animals allowed to survive five hour post oral dosing. During the survival period animals remained separated from their dam but were kept warm. Animals were killed by intracardiac perfusion of a mixed aldehyde fixative. Carbohydrate produced a significant protective effect against neuronal necrosis when administered simultaneously with 1000 mg/kg body weight aspartate. The neuropathological data reported in the study are consistent with available data on aspartame toxicity in infant mice.