Article Figures & Data
Figures
- Figure 1.
A, Training and recording protocol. The animals were trained with 10 odor (20 s)-shock (1 s) pairings. During the 1-min post-shock period, LFPs were recorded together with USVs and behavior; 48 h later, a retention test was conducted using five odor (20 s) presentations during which the animal’s freezing response was assessed. B, Definition of four experimental categories for data analysis. During the 1-min post-shock period, we defined blocks of USV corresponding to successive USV with less than 1 s between each other. When the interval between two USV exceeded 1 s, then a new block was defined (first row). The periods between USV blocks are considered as silent periods. In parallel, the synchronized animal’s behavior (freezing or escape) was detected, and four different combinations were obtained: USV freezing, USV escape, silent freezing, and silent escape. For each combination, only segments longer than 1 s were considered.
- Figure 2.
Repartition of the four defined categories and characterization of two 22-kHz USV types (n = 22 rats). A, Mean (±SEM) proportion of each category per animal over the 1-min post-shock analysis period. B, Mean (±SEM) duration of the different categories and mean (±SEM) number of USV freezing and USV escape emitted during the 1-min post-shock period. C, Mean duration (±SEM) of the two USV subtypes. D, Mean frequency (±SEM) of the two USV subtypes. E, Mean intensity (±SEM) of the two USV subtypes; n = 22 rats, *p < 5 × 10−2, ***p < 5 × 10−3. F, Correlation between the mean number of USV calls recorded during the 1-min post-shock period at training and the freezing score obtained during the retention test in response to the learned odor; *p < 5 × 10−2.
- Figure 3.
PSD of LFP signals and mean power in delta (0–5 Hz) and theta (5–15 Hz) bands. The average PSD (±SEM) is represented on the left part of the figure, and the delta and theta average power (±SEM) is represented on the right part. BLA: n = 14; mPFC: n = 21; and PIR: n = 20; *p < 5 × 10−2, **p < 5 × 10−3, ***p < 5 × 10−4: significant difference between same color-different pattern bars; $p < 5 × 10−2, $$p < 5 × 10−3, $$$p < 5 × 10−4: significant difference between same pattern-different color bars.
- Figure 4.
PSD of LFP signals and mean power in gamma (40–80 Hz) band. The average PSD (±SEM) is represented on the left part of the figure, and the gamma average power (±SEM) is represented on the right part. BLA: n = 14; mPFC: n = 21; and PIR: n = 20; *p < 5 × 10−2, **p < 5 × 10−3, ***p < 5 × 10−4: significant difference between same color-different pattern bars; $p < 5 × 10−2, $$p < 5 × 10−3, $$$p < 5 × 10−4: significant difference between same pattern-different color bars.
- Figure 5.
Characterization of respiratory frequency in the four experimental categories (n = 22 rats). A, Individual examples of the respiratory signal. B, PDF of respiratory frequency. The distributions were obtained using a 0.33-Hz bin. Inset, Average peak frequency (±SEM) in each category.
- Figure 6.
Covariation between delta and theta oscillatory frequencies and respiratory frequency. A, Each graph represents the PSD of LFP signals (left y-axis, black curve) and the PDF of respiration (right y-axis, red curve). The graphs were obtained from LFP signals recorded in the mPFC in the four experimental categories (silent escape, USV escape, silent freezing, and USV freezing). B, 2D matrix histograms obtained from LFP signals recorded in mPFC (n = 21), BLA (n = 14), and PIR (n = 20), y-axis represents LFP frequency and x-axis respiratory frequency. The 2D histogram is normalized so that the total sum is 1, and point density is represented on a color scale ranging from blue to yellow as the point density increases.
- Figure 7.
Modulation of beta and gamma power by the phase of the respiratory cycle. A, Individual traces representing from the top, respiratory signal, USV calls, raw LFP signal recorded in the PIR and its time frequency map (y-axis: LFP signal frequency in Hz, x-axis: time in milliseconds). LFP signal power is represented using a color scale going from blue to red as the power increases. The red vertical plain line represents the transition between expiration and inspiration, while the red vertical dotted line represents the transition between inspiration and expiration. B, Average time frequency map centered on the normalized respiratory cycle, in the four experimental categories. The red vertical dotted line represents the transition between inspiration and expiration phase that was set at 0.4 (this value corresponds to the mean ratio between inspiration and expiration over the four experimental categories). The white horizontal dotted line represents the transition between beta and gamma bands.
- Figure 8.
Beta Activity power time course throughout the normalized respiratory cycle in the three recording sites and in the four experimental categories. Left side, Silent freezing versus USV freezing. Right side, Silent escape versus USV escape. The vertical dotted line on each graph represents the transition between inspiration and expiration phase positioned at 0.4 (this value corresponds to the mean ratio between inspiration and expiration over the four experimental categories). BLA: n = 14; mPFC: n = 21; and PIR: n = 20.
- Figure 9.
Gamma Activity power time course throughout the normalized respiratory cycle in the three recording sites and in the four experimental categories. Left side: Silent freezing versus USV freezing. Right side, Silent escape versus USV escape. The vertical dotted line on each graph represents the transition between inspiration and expiration phase positioned at 0.4 (this value corresponds to the mean ratio between inspiration and expiration over the four experimental categories). BLA: n = 14; mPFC: n = 21; and PIR: n = 20.
- Figure 10.
Schematic summary of the data obtained during silent freezing and USV freezing. During silent freezing, delta frequency covaries with nasal respiratory frequency. In addition, power in the beta band for the PIR and in the gamma band for the three recording sites is modulated in phase with respiration, with higher beta and gamma power during inspiration than expiration. USV freezing emission coincides with a decrease in theta power and an increase in delta and gamma power. In parallel, a deep slow-down of respiratory frequency is observed, with the uncoupling between delta frequency and respiratory frequency. Furthermore, a reorganization of beta and gamma activity power during the respiratory cycle occurs, with increased β power in the PIR during the first half of expiration phase, and increased gamma power in the three recording sites during the second half of expiration.
Extended Data
Extended Data Figure 1-1
Areas targeted by the electrodes (light orange areas) in the three recording sites. Numbers at the bottom indicate the relative position of coronal slices from bregma (adapted from Paxinos and Watson, 2007). mPFC: n = 21; PIR: n = 20; and BLA: n = 14. Download Figure 1-1, TIF file.
Extended Data Figure 3-1
Delta and Theta activity mean power statistical data: ANOVA analysis (upper table) and p values for post-hoc comparisons (lower table). * : p≤5x10-2, ** : p≤5x10-3, *** : p≤5x10-4. Download Figure 3-1, DOCX file.
Extended Data Figure 4-1
Beta band mean power values (+/- sem) in the three recording sites (upper table), ANOVA analysis (middle table), and p values for post-hoc comparisons (lower table). * : p≤5x10-2, ** : p≤5x10-3, *** : p≤5x10-4. Download Figure 4-1, DOCX file.
Extended Data Figure 4-2
Gamma band mean power statistical data in the three recording sites: ANOVA analysis (upper table) and p values for post-hoc comparisons (lower table). * : p≤5x10-2, ** : p≤5x10-3, *** : p≤5x10-4. Download Figure 4-2, DOCX file.
Extended Data Figure 6-1
Examples of raw traces obtained in the same animal in the three recording sites and the four experimental categories. Each panel represents from the top: USVs calls (for the panels on the right), raw respiratory signal, and LFP signals recorded in the BLA, mPFC, and PIR. Download Figure 6-1, TIF file.
Extended Data Figure 7-1
Modulation of β and γ power by the phase of the respiratory cycle. Average time frequency maps centered on the normalized respiratory cycle, in the three-recorded structures (along the vertical axis) and the four experimental categories (along the horizontal axis). On each graph, the red vertical dotted line represents the transition between inspiration and expiration that was set at 0.4, and the white horizontal dotted line represents the transition between β and γ bands. BLA: n = 14; mPFC: n = 21; and PIR: n = 20. Download Figure 7-1, TIF file.
Extended Data Figure 8-1
Beta (upper table) and Gamma (lower table) bands maximum power throughout the respiratory cycle, ANOVA analysis. * : p≤5x10-2, ** : p≤5x10-3, *** : p≤5x10-4. Download Figure 8-1, DOCX file.
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