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Respiratory plasticity induced by intermittent hypoxia following mid‐cervical contusion in unanesthetized rats
Author(s) -
Chiang ShuChi,
Lee KunZe
Publication year - 2016
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.30.1_supplement.1299.1
Subject(s) - hypoxia (environmental) , medicine , intermittent hypoxia , anesthesia , tidal volume , respiratory system , spinal cord , spinal cord injury , chemistry , organic chemistry , psychiatry , oxygen , obstructive sleep apnea
Intermittent hypoxia has been considered as a potential approach to induce respiratory neuroplasticity. The purpose of present study was to investigate the impact of intermittent hypoxia on respiratory function following cervical contusion in unanesthetized rats. Adult male rats were received laminectomy or unilateral contusion at C3–C4 spinal cord using the MASCIS Impactor (height: 6.25 or 12.5 mm). At 4 weeks post‐injury, the breathing pattern of unanesthetized rats was measured by the whole body plethymography before, during and after 10 episodes of 5‐min hypoxia (10 % O 2 , 4 % CO 2 , balance N 2 ) with 5‐min normoxia intervals. The result demonstrated that animals received severe cervical contusion had a lower tidal volume than uninjured animals. Hypoxia induced a significant increase in frequency and tidal volume in uninjured and contused animals. However, there is a progressive decline in the magnitude of hypoxic ventilatory response during intermittent hypoxia. Specifically, the frequency response is gradually reduced in uninjured animals, and the tidal volume response is decreased in contused animals with successive hypoxic stimuli. In addition, the tidal volume was significantly enhanced in contused rats but not uninjured rats at 30 min post‐hypoxia, suggesting intermittent hypoxia can induce long‐term facilitation of tidal volume following cervical contusion. These results demonstrated that intermittent hypoxia can induce differential forms of respiratory plasticity in uninjured vs. contused animals, and it may be a promising neurorehabilitation approach to improve respiratory function after cervical spinal cord injury. Support or Funding Information National Health Research Institutes (NHRI‐EX104‐10223NC), Ministry of Science and Technology (Most 102‐2320‐B‐110‐004‐MY3)