EVIDENCE FOR AN ANXIOGENIC ACTION OF AMPA RECEPTOR ANTAGONISTS IN THEPLUS-MAZE TEST

The effects of the non-NMDA receptor antagonists, the new pha-amino-3- hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA)-selective receptor antagonist, LY326325, and the AMPA/kainate-selective receptor antagoni st, NBQX -7-sulfamoylbenzo(f)quinoxaline-2,3-(1H,4H)dione), on plus-ma ze behavior and locomotor activity were examined. LY326325 induced a d ose-dependent decrease in the per cent time spent in open arms as well as in the per cent entries into the open arms. NBQX caused a dose-dep endent reduction in the per cent time spent in open arms but had no ef fect on the per cent entries into the open arms. The behavioral action s of the AMPA receptor antagonists were observed at doses which had no influence on the locomotor activity of the animals. Based upon the cu rrent findings it is suggested that AMPA receptor antagonists produce a dose-dependent increase of anxiogenic behavior in the plus-maze test situation.