Figure 2.

Increased slow-oscillatory UP/DOWN state dynamics of the membrane potential of dentate granule cells in post-SE rats. A1, Neurolucida reconstruction of the morphology of a recorded dentate granule cell from a control rat (top) and voltage responses to intracellularly injected depolarizing and hyperpolarizing current pulses (500 ms duration, bottom). A2, Top, V_m of the cell illustrated in A1 during a 60 s recording. Bottom, Time–frequency power spectrogram (5 s sliding window, 0.2 s steps) corresponding to the top trace. Superimposed white line represents the time-varying power values in the SWO frequency range (0.1-2 Hz). Dashed white line (green arrow) indicates the SWO detection threshold used to detect SWO epochs (horizontal green bars). A3, Top, Distribution of V_m values for the trace shown in A2, Bottom, Relative proportion of DGCs according to the distribution of their V_m (Ske., skewed; Sym., symmetric; n = 10). B, Same as in A for the post-SE condition. Note the presence of a continuous band in the slow-frequency range (∼0.8 Hz), and bimodal distribution of the V_m in the DGC from post-SE, but not control, rat (Bim., bimodal). C, Power spectrum of the traces shown in A (blue) and B (red). D, Average power spectrum for all recorded DGCs in control (blue line; n = 10) and post-SE (red line; n = 8). E, Autocorrelogram of the traces shown in A (blue) and B (red). F, Mean autocorrelogram for all recorded DGCs in control (blue line; n = 10) and post-SE (red line; n = 8). Light blue- and pink-shaded areas correspond to ±SEM.