Figure 2.

Loss of task-related θ frequency modulation after hippocampal Aβ injection. A, Examples of raw LFP (3 s epochs) for vehicle-treated (top) and Aβ-treated animals (bottom) during exploration of familiar (black line) and new (gray line) items, on the 21st day after the injections. B, Averaged power spectra in the 0–10 Hz band, analyzed from LFP epochs during exploration of familiar or new items on the 21st day after the injections. C, Progressive evolution of peak power spectrum frequency during exploration of familiar (black diamond) or new (gray diamond) items for vehicle-treated (top) and Aβ-treated animals (bottom) (n = 8 to 12 sequences per class). Data are represented as mean ± SEM, *p < 0.05; ANOVA with group and day as factors. θ frequency is modulated by novelty in vehicle but not in Aβ-treated animals.