Fig. 2: Breathing-related OB 4 Hz organizes neural firing in the dorsomedial prefrontal cortex during freezing. | Nature Communications

Fig. 2: Breathing-related OB 4 Hz organizes neural firing in the dorsomedial prefrontal cortex during freezing.

From: Breathing-driven prefrontal oscillations regulate maintenance of conditioned-fear evoked freezing independently of initiation

Fig. 2

a Representative spectrogram of OB and dmPFC activity and associated coherogram during a test session. Note the prominent 4 Hz oscillation in both structures during freezing epochs (black lines). b Averaged coherence between the OB and dmPFC during freezing (blue) and non-freezing (grey) periods. Error bars are SEM. Inset: average coherence of 3–6 Hz band. (Paired Wilcoxon signed-rank test: Signed Rank statistic = 1, p = 6.1e−5, n = 15). c Averaged Granger causality during freezing from OB to dmPFC (black) and from dmPFC to OB (green). Error bars are SEM. Inset: mean Granger causality in the 3–6 Hz band. (Paired Wilcoxon signed-rank test: Signed Rank statistic = 97, p = 0.0353, n = 15). d Averaged power spectra during freezing in sham (black) and bulbectomized (OBX) (red) mice. Error bars are SEM. Inset: signal-to-noise ratio of 3–6 Hz band during freezing periods. (Wilcoxon rank-sum test: Signed Rank statistic = 180, p = 5.1e−4, n = 15 and n = 4). e Averaged OB spectrogram triggered on freezing onset and offset in control mice. Note the appearance of strong activity in the 4 Hz band. f, g As in (e) for the dmPFC in control (f) and bulbectomized (g) mice. Note the appearance of 4 Hz in control but not in bulbectomized mice. h Averaged dmPFC-OB coherogram triggered on freezing onset and offset in control mice. i Phase histograms of an example dmPFC unit modulation by OB LFP showing clear gain in phase locking during freezing (left) relative to active (right) epochs. j Cumulative distribution of log-transformed Rayleigh’s test Z of dmPFC putative principal neurons (PNs) and interneurons (INs) modulation by OB LFP. Inset: percentage of significantly modulated neurons using Rayleigh’s test with p = 0.05. k Percentages of dmPFC units modulated by the OB LFP during active behaviour and during freezing using Rayleigh’s test with p = 0.05. The proportion of OB modulated neurons increases significantly for freezing state. (45% vs 23%, chi2stat = 9.82, p = 0.0017, n = 100 units). l Modulation index of firing rate of all neurons between freezing and active periods. On average units decrease their firing rate during freezing. (One-sample two-sided Wilcoxon signed-rank test with 0: zval = −3.4314, p = 6.0e−04, n = 100 units). In all panels, boxplots show median and interquartile range.

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