In the course of searching for biologically active substances among derivatives of glutamic and aspartic acid by employing experiments on radioligand binding [4], we have shown that certain N-and O-derivatives of these stimulant amino acids (SAA) can interact with" glutamaterecognizing sites" of rat brain synaptic membranes. We studied the biological activity of N-acyl derivatives of glutamic and aspartic acid (I-XVII) by injecting them directly ...