Fig. 2.

Ventilatory responses to hypoxia and hypercapnia in CSE^+/+ and CSE^−/− mice. Ventilation was measured in unsedated mice by whole body plethysmography under normoxia (21% O₂), hypoxia (12% O₂), and hypercapnia (5% CO₂). Hypoxia and hypercapnia lasted for 5 min. Representative tracings of breathing are shown in A and average data of minute ventilation (V_E) in response to 12% O₂, i.e., hypoxia (B) and 5% CO₂ i.e., hypercapnia (C). The data presented are mean ± SEM from eight CSE^+/+ and CSE^−/− mice each. **, P < 0.01; n.s. (not significant), P > 0.05.