Fig. 6

Effects of minocycline (MINO) on ventilatory responses to mild (13% O₂) and severe (7% O₂) hypoxia. Mean values were compared among the baseline (0–2 min before hypoxia), end-hypoxia (5–7 min in mild hypoxia and 6–8 min in severe hypoxia), and recovery (16–18 min) phases. A, B Comparison of respiratory rate (RR) among three oxygen phases during mild and severe hypoxia. RR was higher during hypoxia than in other phases (for details, see Results). C, D Comparison of tidal volume (\({\dot {\text V}} \)T) among three oxygen phases during mild and severe hypoxia. E, F Comparison of minute ventilation (\({\dot {\text V}} \)E) among three oxygen phases during mild and severe hypoxia. In both mild and severe hypoxia, \({\dot {\text V}} \)E was larger during hypoxia than during baseline and recovery (p < 0.01). In severe hypoxia, \({\dot {\text V}} \)E was larger than that in mild hypoxia (p < 0.01). * p < 0.05, ** p < 0.01