γ-Kainylglutamic acid (γ-Kainic acid-glutamic acid), a dipeptide derived from kainic and L-Glutamic acids, is a selective antagonist of amino acid induced neuroexcitation with anticonvulsant properties. γ-Kainylglutamic acid inhibits the stimulation of Na + fluxes induced in brain slices by the neuroexcitant N-methyl-D-aspartic acid. γ-Kainylglutamic acid is also effective in protecting mice from picrotoxin-induced convulsions with an EC 50 value of 0.17 μmol.