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Unilateral Denervation of the Diaphragm Muscle Increases Central Drive Only During Ventilatory Behaviors
Author(s) -
Gill Luther,
Mantilla Carlos,
Sieck Gary
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.1013.5
Subject(s) - diaphragm (acoustics) , denervation , hypercapnia , phrenic nerve , control of respiration , anesthesia , ventilation (architecture) , medicine , respiratory system , anatomy , physics , acoustics , loudspeaker , thermodynamics
Compensatory respiratory plasticity is critical to preserve breathing capacity after phrenic denervation (DNV), when the contribution of the ipsilateral phrenic motor neuron (PhrMn) pool is abolished and the force generating capacity of the diaphragm muscle (DIAm) is compromised. In rats, ventilation is maintained after DNV, and this is most likely mediated by an increase in central drive to the contralateral PhrMn pool. The extent of central drive to PhrMns was estimated by measuring the root mean square (RMS) of DIAm EMG at 75ms (RMS 75 ) after the onset of activity. Transdiaphragmatic pressure (Pdi) was measured to estimate DIAm force. We hypothesized that after unilateral DNV central drive to the contralateral PhrMn pool increases across motor behaviors. Immediately following DNV, there was a significant increase in RMS 75 during ventilatory behaviors (eupnea, and hypoxia‐hypercapnia). RMS 75 did not change during non‐ventilatory behaviors (airway occlusion). These results indicate that after DNV there is: 1) an increase in central drive to the contralateral PhrMn pool during ventilatory behaviors such that Pdi was maintained; 2) central drive to the contralateral PhrMn pool was unchanged during more forceful (greater than ~50% Pdi max ) non‐ventilatory behaviors, suggesting that central drive was near maximum. These results highlight the compensatory plasticity in the neural control of the DIAm and the importance of measuring multiple motor behaviors.