The present invention relates to novel nucleic acid ligands or aptamers that bind to and inhibit the activation of the .alpha.-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) subtype of ionotropic glutamate receptors. Also disclosed is a novel combination of technologies, i.e., SELEX and laser pulse photolysis for the selection and screening of aptamers that inhibit receptor function and are useful therefore, in the treatment of diseases associated with excessive activation of ionotropic glutamate receptors.