Representative integrated hypoglossal neurograms before, during, and 60 min following intermittent (top) or sustained (middle) hypoxia or no hypoxia (time control, bottom). Relative to baseline (indicated by dotted line), hypoglossal burst amplitude was increased 60 min following intermittent, but not sustained hypoxia. When hypoxia is not presented, hypoglossal motor output remains stable over time (time control). Short bar = 5 min; long bar = 25 min.