Respiratory motor responses to cranial nerve afferent stimulation in rats

F. Hayashi, D. R. McCrimmon*

*Corresponding author for this work

Research output: Contribution to journalArticle

26 Scopus citations


It was hypothesized that, because rats appear to lack a prominent disynaptic projection from the dorsal respiratory group to phrenic motoneurons (Phr), they would lack the short-latency excitation of Phr output seen in cats in response to stimulation of some cranial nerve afferents. Single-pulse superior laryngeal nerve (SLN) stimulation elicited a short- latency bilateral excitation of glossopharyngeal (IX) and hypoglossal (XII) nerves and an ipsilateral excitation of pharyngeal branch of vagus (PhX) in 67% of rats, but no excitation of Phr. Vagus (X) stimulation elicited a bilateral excitation of Phr and a predominantly ipsilateral excitation of IX and PhX. Single-pulse stimulation of SLN or X also elicited longer-latency, bilateral decreases in activity of all recorded nerves. Repetitive stimulation (50 Hz) of SLN or X suppressed inspiratory activity and prolonged expiration. Lung inflation (7.5 cmH2O) inhibited Phr and PhX activity; X stimulation inhibited Phr but prolonged PhX activity. In conclusion, rats predictably lack the SLN-induced short latency Phr excitation but exhibit other short-latency reflexes for which the underlying circuitry is not clear.

Original languageEnglish (US)
Pages (from-to)R1054-R1062
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Issue number4 40-4
StatePublished - Oct 1996


  • Breuer-Hering reflex
  • airway reflexes
  • control of breathing
  • pulmonary reflexes
  • swallowing

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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