Selective Coupling between Theta Phase and Neocortical Fast Gamma Oscillations during REM-Sleep in Mice
Figure 5
Gamma and fast gamma oscillations are differentially phase-locked to theta.
A and B: Mean amplitudes of neocortical gamma (A, 40–100 Hz) and fast gamma (B, 120–160 Hz) plotted according to the phase of theta in active waking (black dots) and REM-sleep (blue dots). Amplitude maxima of gamma occur at the positive peak of the theta wave in parietal cortex (0 degrees), while the amplitude maxima of fast gamma occur at 30 degrees, on the falling flank of the positive peak of the theta wave. C: Time-frequency plot of mean amplitude distribution time-locked to the theta peak (n = 9 mice). The positive peaks of the averaged theta waves correspond to 0 s. Bottom panel shows the theta peak-locked averaged raw signal.