Figure 8
Sharp wave ripple complexes in degus. (A) Representative example of a sharp wave ripple complex (SWR) recorded simultaneously at four different locations (one tetrode per row; from top to bottom: above, inside, inside and below the CA1 pyramidal cell layer). Left: histology of degu XII showing the position of each tetrode (green arrow). Center: local field potential during a 0.6 s window (the same for all tetrodes). Right: corresponding spectrogram obtained with the wavelet transform. White dashed lines: 120 and 240 Hz. (B) Mean (top) and standard deviation (bottom) of power spectral density for the distribution of 2 s windows corresponding to all selected channels in open field recordings (grey), for the selection of windows with low mean running speed (6% of windows; black; cutoff: 1 cm s−1) and for the selection of windows within prolonged periods of low theta amplitude (3%; orange). Dashed lines: 120 and 240 Hz. (C) Mean count of SWR events for consecutive 1 m windows (1 bar per window) during consecutive rest (grey) and open field (red) sessions. (D) As (C) but for rest (grey), open field (grey) and object (green) sessions in the novel location experiment. More events occurred during rest (mean: 6.7 min−1) than during sessions with objects (mean: 2.3 min−1) or open field sessions (mean: 0.5 min−1) (Kruskal–Wallis test H(2): 37.3, p: 10–8; Tukey–Kramer post-hoc analysis indicated that all 3 session types where significantly different from each other, p < 0.01).
