We examined the effect of an AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole) antagonist, 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo (F) quinoxaline (NBQX), on rat cerebellar Purkinje cell loss and hippocampal pyramidal CA1 cell loss, after 10 minutes of global cerebral ischemia. NBQX was given intraperitoneally in a dose of 30 mg kg-1 at the end of ischemia, and 10 and 25 minutes later. Rats subjected to ischemia without post-ischemic administration of NBQX served as controls. Four days after ischemia the cerebellar Purkinje cell density was higher and the density of acidophilic (dead) Purkinje cells lower in the NBQX treated animals compared with the control animals (p = 0.01 and p less than 0.005 respectively). There was partial to total loss of pyramidal neurons in the CA1 region of the dorsal hippocampus in control animals, but no CA1 pyramidal neuron loss in the NBQX treated animals (p = 0.001).