Figure 5—figure supplement 6. | On cross-frequency phase-phase coupling between theta and gamma oscillations in the hippocampus

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On cross-frequency phase-phase coupling between theta and gamma oscillations in the hippocampus

Figure 5—figure supplement 6.

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Federal University of Rio Grande do Norte, Brazil
Figure 5—figure supplement 6.
Download figureOpen in new tabFigure 5—figure supplement 6. Lack of theta-gamma phase-phase coupling during transient gamma bursts.

(A) Examples of slow-gamma bursts. Top panels show raw LFPs, along with theta- (thick blue line) and slow gamma-filtered (thin red line) signals. The amplitude envelope of slow gamma is also shown (thick red line). The bottom rows show gamma and accelerated theta phases (m = 5), along with their instantaneous phase difference (Δφ1:5). For each gamma sub-band, a ‘gamma burst’ was defined to occur when the gamma amplitude envelope was 2SD above the mean. In these examples, periods identified as slow-gamma bursts are marked with yellow in the amplitude envelope and phase difference time series. Notice variable φ1:5 across different burst events. (B) The left panel shows n:m phase-locking levels for theta phase and the phase of different gamma sub-bands (1 s epochs); for each gamma sub-band, Rn:m values were computed using only theta and gamma phases during periods of gamma bursts. The right panels show original and surrogate (Random Permutation/Single Run) distributions of Rn:m values (n = 4 animals).

DOI: http://dx.doi.org/10.7554/eLife.20515.019