Figure 3.

Stimulation during inspiration leads to an increase in the respiratory rate. (a) Thoracic breathing movements recorded with the piezo-sensor. Upward deflection indicates inspiration. Stimulation (blue bars, pulse length 20 ms) during inspiration leads to a decrease in the interval and, thus, (b) to an increase in the respiratory rate (* p < 0.001; n = 8; RM ANOVA on Ranks). After cessation of stimulation, the respiratory rate recovered to baseline levels. (c) Example trace showing the effect of a single light pulse during inspiration. (d) When the light pulse (blue bar in c) was applied during inspiration, the duration of the breath was reduced by the stimulation as compared with the pre-stimulus and the post-stimulus duration (* p < 0.05; One Way RM ANOVA; n = 3 mice). (e) The interval after the stimulation (stim) was also reduced as compared with the pre-stimulus interval (* p < 0.05; One-tailed paired t-test; n = 3 mice). (f) The breathing amplitude was, however, not significantly changed (p > 0.05; One way RM ANOVA; n = 3 mice). Lines in (d–f) show the median (magenta) and the mean (green).