[Breath changes induced by short chemosensory stimuli cannot be intentionally suppressed].

Introduction: Breathing changes induced by repeated short olfactory stimuli are used as an objective indicator of the integrity of the olfactory system. Until now, it has not been investigated whether chemosensorically induced changes in inspiratory and expiratory time parameters can be suppressed intentionally. The same applies to breathing changes due to weak CO stimuli.

[Hydrogen sulphide stimuli shorten exhalation during sleep as well as in wakefulness].

Background: In the attentive waking state, pleasant odours often prolong inhalation while unpleasant odours often shorten the exhalation. It should be checked whether this induced breathing pattern is maintained even during sleep.

Methodology: 23 healthy normosmic adults were examined by polysomnography for one night and randomized pulsed either with HS, phenylethyl alcohol (PEA) or CO via a flow olfactometer.

[Aerobic exercises during mouth breathing do not change the detection threshold of H2S].

Background: In a previous study, the detection threshold for H2S during aerobic exercise worsened with forced nasal breathing. The cause remained unclear. It is to be examined how the detection threshold changes with exclusive mouth breathing.

[Aerobic exercises worsen the detection threshold of short H2S pulses].

Background: Whether smelling is reduced during aerobic exercise is described contradictorily in the sparse literature.

Material And Methods: To clarify this question, in healthy subjects the passive detection thresholds for short HS stimuli were determined by means of a flow olfactometer in an inspiration-synchronous manner during nasal breathing in a staircase procedure during a resting phase, a subsequent submaximal load on a bicycle ergometer and a subsequent recovery phase. In parallel, the measurements of heart rate, blood pressure, blood lactate and body temperature were monitored to confirm an aerobic exercise.

[On the assessment of spontaneous respiratory changes in respiration-olfactometry].

Introduction: Alterations of breathing pattern evoked by odors are used to proof the integrity of the olfactory system in the sense of respiratory olfactometry. Spontaneous breathing changes normally cannot be distinguished from evoked changes. It is therefore necessary to repeatedly apply stimuli with a pure odorant during tidal breathing, randomized with neutral air, to detect a majority of olfactory-evoked respiratory changes.