Fig. 1: Rapid dynamic breathing patterns characterize the awake, normally behaving, state.

a Schematic of experimental setup and example plethysmograph recording showing quantified parameters. b Representative recordings from an awake freely behaving mouse breathing room air (b₁), during near maximal chemoreflex stimulation with 10% O₂; 5% CO₂ (b₂) or 10% CO₂ (b₃) and following transition to the anesthetized state with 1.5% isoflurane in room air (b₄). Panels show plethysmograph pressure waveforms (top) and corresponding 3-breath moving average of breathing frequency (black) and breathing acceleration (violet). Magenta stars indicate breathing bouts that exceed 8 Hz. c PCA of breathing patterns generated spontaneously in the awake state (22,345 breaths from n = 6 mice). Magenta colored dots correspond to the onset (first 5 breaths) of rapid breathing bouts as shown in b₁. d PCA of spontaneous, chemoreflex-driven, and anesthetized breathing patterns (d₁; 67,579 breaths from n = 6 mice) and relative contributions of respiratory parameters to PCs 1 and 2 (D₂). e Quantified average acceleration (left) and number of rapid breathing bouts per minute (right). n = 6; one-way RM ANOVA with Tukey’s multiple comparisons tests. f Probability density histograms (top) and mean values from each mouse (n = 6; bottom) comparing breathing frequencies (left) and peak inspiratory pressures (right) during each condition. Inset illustrates the rapid breathing frequencies (~8–12 Hz) that characterize the awake spontaneously breathing state. Breathing frequencies under spontaneous conditions were bimodal and were separated into “slow” and “fast” modes for analysis. One-way RM ANOVA with Tukey’s multiple comparisons tests. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001. Means±SE. Source data are provided as a Source Data file.