Fig. 2.

Spontaneous field potential recordings reveal epileptiform activities and HFOs components in the subiculum. (a) Representative traces of long-term LFP showing spontaneous activities in each subfields. Calibration: 0.1 mV, 10 s. (b) Coupling activities between the subiculum and CA1 in No-HS. Magnified traces of a single event (indicated by box in upper panel) are shown in the lower panel. Calibration: 0.1 mV, 10 s (upper panel), 50 ms (lower panel). (c) Amplitude (upper panel) and number of events (lower panel) of LFP analyzed quantitatively in the subiculum during 10-min recordings. Number of events in No-HS and HS is significantly higher than in the Ex-hipp, even though the amplitudes are not significantly different. *p < .05 and **p < .01, Tukey-Kramer test after one-factor ANOVA. N.S.: not significant. (d) Magnified traces of single LFP events in the subiculum. Five consecutive traces are overlapped (the last trace is indicated by the red line), indicating similar waveforms (unfiltered). Traces with application of a high-pass filter (HPF) at 100 Hz. Calibration: 0.1 mV (unfiltered), 50 μV (HPF), 50 ms. (e) Representative time-frequency spectral analysis of 10 averaged consecutive events in the subiculum demonstrates clear spot-like activity (upper panel). Scale bar: 100 ms. The frequency at peak power does not differ significantly (lower panel). Error bars, S.E.M.