Interregional power correlations during ripples and fast gamma oscillations. A, Comodugrams during ripples between a reference site (red dot) and other sites in the cell body layers (black dots). Each comodugram plots the matrix of correlation coefficients (r) between the spectral power at the reference site (red dot; x-axis) and power at the target site (black dot; y-axis) for each pairing of frequencies. Note high power correlations in the 140–250 Hz band between CA1 sites and corresponding power increase at <130 Hz in the CA3 and dentate regions. The white arrow indicates correlation discontinuity. B, Same as in A but during fast gamma events.