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Daily Acute Intermittent Hypoxia Enhances Inspiratory Activity in Non‐Diaphragm Breathing Muscles
Author(s) -
Weltman Joel,
NavarreteOpazo Angela,
Johnson Rebecca,
Mitchell Gordon
Publication year - 2015
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.29.1_supplement.656.7
Acute intermittent hypoxia (AIH; 5 min 10.5% O 2 /5 min 21% O 2 ; 10 cycles) elicits long‐lasting facilitation of diaphragm and T2 external intercostal muscle activity of awake, freely behaving rats. Here, we tested the hypothesis that daily AIH (dAIH) reveals inspiratory activity in three accessory breathing muscles not normally active in awake, freely behaving rats. Sprague Dawley rats (Harlan colony 211, 11‐16 wks old) were chronically instrumented with EMG radiotelemeter electrodes in the sternomastoid, scalene medius, serratus dorsalis and diaphragm muscles. EMG's were recorded with room air breathing (FIO 2 /FICO 2 =0.21/0.0) and with maximal chemoreceptor activation (FIO 2 /FICO 2 = 0.105/0.07, MCS). Values were compared before and after dAIH (AIH for 7 consecutive days). Preliminary data show minimal inspiratory activity during room air breathing or MCS in non‐diaphragm muscles before dAIH; however, coordinated inspiratory activity is obvious in sternomastoid and serratus dorsalis muscles following dAIH during both room air and MCS. Recruitment and coordination of non‐diaphragm muscles of breathing would be beneficial in states of weakened, paralyzed or otherwise impaired diaphragm activity. Supported by NIH HL69064, NIH UL1TR000427, and DoD W81XWH‐13‐1‐0410.