Abstract— The effects of l-glutamate and a number of structural analogues on the spontaneous release of [3H]dopamine from slices of rat striatum were examined. Glutamate, and other excitatory amino acids produced a marked stimulation of [3H]DA release which was Ca2+-dependent and unaffected by either procaine or tetrodotoxin. The glutamate-stimulated release was abolished in kainate-lesioned striatum. The action of glutamate was effectively antagonised by glutamamate diethylester and 2-amino-4-phosphonobutyric acid, but only weakly by l-methionine-dl-sulfoximine. Other proposed amino acid antagonists were inactive. The likely site of the releasing action of l-glutamate on presynaptic sites on nigro-striatal DA terminals is discussed.