Laryngeal afferents activated by phenyldiguanide and their response to cold air or helium-oxygen.

摘要: Abstract In anesthetized cts, sensory in the superior laryngeal nerves (SLN) were identified with respect to their response (1) phenyldiguanide (PDG) i.v., (2) mechanical stimulation and (3) lowering temperature an isolated tracheolaryngeal segment. The activity originating from 107 SLN afferent units activated by PDG was recorded using glass microelectrodes nodose ganglion. All tested increased discharge rate during direct touching of airway mucosa. None showed flow or pressure related abrupt changes constant transmural Fifteen inhibited cold air. Sixty-two significantly firing when temparature approached 18°C, reached a peak near 15°C, then decreased stopped. air compared heliox (79% He-21 O 2 ), which enhanced respiratory heat loss conduction. higher (+ 356% + 246% air), threshold (25° C ± 1.0° ) amd range broader (25-11.5°C). Present results show that large proportion (58%) fibres are likely non-proprioceptive units, stimulated cooling inspired gas. Thermosensitive upper airways may act as sensors thermal flux through wall more than detectors absolute value lumen.