a.) Input-output curves in response to perforant-path stimulation. Hilar evoked responses to perforant-path stimulation were completely abolished in all animals by infusion of TTX into the angular bundle. b.) Gamma power was dramatically decreased by TTX infusion in both X-irradiated and sham-treated groups (n=6 X-ray, 5 sham animals; p=0.004 for sham effect of TTX, p= 0.04 for X-ray, two-tailed paired Student’s t-test). Gamma burst amplitude was also significantly reduced in irradiated animals (n=6 X-ray, 5 sham animals; p=0.02 for sham effect of TTX, p= 0.03 for X-ray, two-tailed paired Student’s t-test).