De (LY404187), N-(2-(4-(thiophen3-yl)phenyl)propyl)propane-2-sulfonamide (LY392098), (R)2-(4-(3,5-difluorobenzoylamino)phenyl)-1-(2-propanesulfonamido)-propane (LY450108), LY451395, and LY503430] (Ito et al., 1990; Copani et al., 1992; Arai et al., 1996, 2000; Baumbarger et al., 2001a,b). Although positive AMPA receptor modulators fall into three structural classes, the most important difference b