Table 3.

Respiratory changes to hypoxia (13.3% O₂ in air) across brain-state alternations

	REM-like		Transition		nREM-like
	AIR	13.3% O2	AIR	13.3% O2	AIR	13.3% O2
Respiratory period (s)	0.42 ± 0.02	0.38 ± 0.01*	0.42 ± 0.02	0.39 ± 0.02*	0.47 ± 0.01	0.42 ± 0.02*
		−11.0 ± 2.1% (7.5 × 10−4)		−8.9 ± 2.1% (1.7 × 10−3)		−10.3 ± 2.7% (3.0 × 10−3)
Tidal volume (ml)	1.81 ± 0.16	1.79 ± 0.14	1.79 ± 0.167	1.79 ± 0.15	1.87 ± 0.19	1.87 ± 0.19
		−0.3 ± 0.3% (0.40)		+0.3 ± 2.5% (0.49)		+0.1 ± 3.2% (0.49)
Minute ventilation (ml/min × 100 g)	75.4 ± 9.4	82.1 ± 9.3*	74.7 ± 9.9	79.3 ± 10.2*	70.6 ± 9.2	78.2 ± 9.6*
		+9.3 ± 1.6% (3.5 × 10−3)		+6.3 ± 2.0% (0.04)		+9.3 ± 1.5% (0.002)
Sigh rate (s/h)	36.6 ± 13.0	164.0 ± 34.5*	42.2 ± 13.3	145.6 ± 26.7*	15.9 ± 4.2	72.5 ± 22.7*
		+579 ± 212% (7.8 × 10−4)		+377 ± 118% (4.5 × 10−4)		+431 ± 169% (0.01)
Peak ∫DIAEMG (a.u.)	0.97 ± 0.21	1.17 ± 0.46	0.93 ± 0.2	1.18 ± 0.45	1 ± 0.2	1.17 ± 0.44
		+5.4 ± 23.8 (0.27)		+12.6 ± 23.0 (0.23)		+2.4 ± 22.7 (0.29)
Peak ∫GGEMG (a.u.)	0.85 ± 0.27	0.72 ± 0.21	0.82 ± 0.25	0.72 ± 0.22	1 ± 0.31	0.72 ± 0.22
		−3.6 ± 9.8% (0.25)		−3.1 ± 9.9% (0.3)		−17.0 ± 8.8% (0.07)
Peak ∫ABDEMG (a.u.)	1.23 ± 0.21	1.50 ± 0.40	1.17 ± 0.19	1.32 ± 0.32	1 ± 0.12	1.49 ± 0.41
		+19.9 ± 19.5% (0.19)		+10.8 ± 14.3 (0.26)		+43.6 ± 29.6% (0.11)

Peak EMG activity is calculated based on baseline level of activity during nREM-like state in air breathing. Averaged respiratory period, tidal volume, minute ventilation, sigh rate, and integrated peak EMG activity for DIA, GG, and ABD muscles for REM-like, transition, and nREM-like states during control and hypoxia. Values in italics indicated the percentage of change compared with control (AIR) measurements for each state, and values in parentheses indicates statistical changes significance (p values) within state (with asterisks indicating statistical significance of the relative changes).