Table 2– Negative pressure pulse data collected during wakefulness

Pressure reflex and stimulus characteristics	Pre-pentobarbital	Post-pentobarbital	Pre-placebo	Post-placebo
Excitation onset latency ms	27±5	28±3	26±5	21±2
Excitation peak amplitude % baseline	224±30	227±34	236±34	242±28
Excitation peak latency ms	36±4	38±3	42±8	34±4
Minimum mask pressure cmH₂O	-16±2	-17±2	-19±2	-17±1
Number of artefact-free pulse presentations	39±3	35±3	41±2	34±3

Data are presented as mean±sem. There were no significant differences between conditions for genioglossus reflex characteristics or stimulus magnitudes. n = 10.