Kainate-induced retina amacrine-like cell damage is mediated by AMPA receptors

WE investigated the effect of domoate, kainate and AMPA on Ca-45(2+) uptake and on metabolic activity of cultured chick amacrine-like cells, as measured by reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Domoate and kainate stimulated Ca-45(2+) uptake and decreased MTT reduction, in a LY 303070-sensitive manner. AMPA caused a small increase on Ca-45(2+) uptake, but it was without effect on MTT reduction. AMPA reduced both the Ca-45(2+) entry and neurotoxicity induced by kainate, and cyclothiazide enhanced both the Ca-45(2+) entry and neurotoxicity induced by AMPA. The results indicate that the AMPA receptors are the non-NMDA glutamate receptors involved in excitotoxicity. (C) 1998 Lippincott Williams & Wilkins.