Coherent averaging of spontaneous surges of blood pressure at different ambient temperatures.

<p>The panels show time series of systolic blood pressure (ΔSBP, panels A, C, E) and heart period (ΔHP, panels B, D, F) during spontaneous SBP surges (detection threshold = 5 mm Hg) as a function of the wake-sleep state and T_a. The time series were normalized by subtraction of their respective baseline values and synchronized at the peak SBP increase. Panel G summarizes the interpretation of ΔHP during spontaneous SBP surges <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047032#pone.0047032-Silvani2" target="_blank">[28]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047032#pone.0047032-Silvani3" target="_blank">[31]</a>. The negative ΔHP trough (i.e., cardiac acceleration) before the SBP surge peak is consistent with central autonomic control of the heart. The positive ΔHP peak (i.e., cardiac slowing) after the SBP surge peak is consistent with baroreflex cardiac control. Accordingly, the statistical analysis in panels A–F was performed on the peaks of ΔSBP and ΔHP and on the trough of ΔHP. Panel H shows the frequency of occurrence of spontaneous SBP surges expressed as the number of surges in 10 min of each wake-sleep state. Data in all panels are mean values ± SEM in TG (n = 11) and WT (n = 12). * and †, <i>P</i><0.05, TG vs. WT (same T_a) and 20°C T_a vs. 30°C T_a (same group), respectively (<i>t</i>-test). The † symbol between brackets applies to each mouse group. Detailed ANOVA results are reported in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047032#pone.0047032.s005" target="_blank">Table S5</a>. Abbreviations have the same meaning as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047032#pone-0047032-g002" target="_blank">Figure 2</a>.