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Effects of airway pressure, hypercapnia, and hypoxia on pulmonary vagal afferent activity in the alligator
Author(s) -
Marschand Rachel,
Wilson Jenna,
Burleson Mark L,
Crossley Dane A,
Hedrick Michael S
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.714.13
Subject(s) - alligator , pulmonary stretch receptors , hypercapnia , anesthesia , stretch receptor , vagus nerve , hypoxia (environmental) , anatomy , respiratory system , chemistry , biology , medicine , receptor , oxygen , paleontology , organic chemistry , stimulation
The American alligator ( Alligator mississippiensis ) is an aquatic vertebrate that dives and has a periodic breathing pattern. The effects of airway pressure, hypercapnia, and hypoxia on dynamic and static responses of pulmonary stretch receptors (PSR) were studied in juvenile alligators (mean mass = 246 g) at room temperature (24°C). Alligators were initially anesthetized with isoflurane, pithed, tracheotomized and attached to a small animal ventilator. The vagus nerve (cranial nerve X) was exposed, sectioned and submerged in mineral oil. Nerve filaments were teased from the nerve trunk and placed over platinum electrodes for differential nerve recording. Afferent tonic and phasic activity was recorded. The majority of receptors appeared to be slowly‐adapting PSRs (SAR) with varying thresholds and degrees of adaptation and no CO 2 sensitivity. Dives were simulated in order to characterize receptor activity during and after prolonged periods of inflation and deflation. Some stretch receptors showed a change in dynamic response, exhibiting inhibition after lung inflation and potentiation after lung deflation. These airway stretch receptors may be involved in buoyancy control and/or recovery of breathing patterns and lung volume during pre– and post‐diving behavior and apneic periods. Supported by NSF CAREER IOS 0845741 (DAC).