1) High concentration of sodium glutamate (as well as sodium aspartate) which is applied into grey matters of motor cortex in dogs, monkeys and men, generates clonic convulsions with very short latent periods.2) Small dose of sodium glutamate which is introduced into circulation in dogs improves the differentiation of conditioned salivary reflexes during 20 minutes after its administration, and continues its action for some hours.3) The above two aspects of the effect of sodium glutamate must be attributable to the direct physiological action of the chemicals on the central nervoos system in higher animals.