Figure 4
Cardiorespiratory interaction under hypoxia in the toad Rhinella schneideri. Waterfalls showing the spectra calculated (A) and associated histograms for lung inflation cycles (B) in one representative toad before and after selective autonomic blockade (atropine + sotalol) under hypoxic conditions (FIO2: 0.05). The respiratory-related peak in the heart rate variability was mostly abolished by the parasympathetic blockade (atropine). β-adrenergic after muscarinic blockade further diminished, but not eliminated, the remaining respiratory peak.
