Premium
Diaphragm Activation via High Frequency Spinal Cord Stimulation (HF‐SCS) in a Rodent Model of Spinal Cord Injury
Author(s) -
Kowalski Krzysztof E,
Hsieh YeeHsee,
Dick Thomas E,
DiMarco Anthony F
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.lb879
Subject(s) - spinal cord , spinal cord injury , medicine , diaphragm (acoustics) , cord , anesthesia , stimulus (psychology) , diaphragm muscle , stimulation , breathing , motor unit , central nervous system , neuroscience , respiratory system , anatomy , biology , surgery , psychology , physics , psychiatry , acoustics , loudspeaker , psychotherapist
Objective HF‐SCS is a novel technique of inspiratory muscle activation involving activation of spinal cord pathways. All previous studies of this method were performed in a dog model of spinal cord injury. Since the rodent respiratory system is also a relevant model for study of neuronal circuitry function and this species is more accessible, we sought to a) evaluate the effects of HF‐SCS and b) determine the methodology of application of this technique in rats. Methods In 9 rats, diaphragm multiunit and single motor unit EMG activity was assessed during spontaneous breathing and HF‐SCS applied on the ventral epidural surface of the spinal cord at the T2 level following C1 spinal section. Results Mean maximum firing frequencies of the diaphragm during spontaneous breathing and HF‐SCS were 23.3 ± 1.4 Hz (range: 9.8 – 51.6 Hz) and 26.6 ± 1.3 Hz; range: 12.0 – 72.9 Hz, respectively, at comparable inspired volumes. Moreover, HF‐SCS was successful in pacing these animals over a 60‐min period without evidence of system fatigue. Conclusion Our results suggest that, similar to the dog model, HF‐SCS in rodents results in activation of spinal cord tracts which synapse with the phrenic motoneuron pools, allowing processing of the stimulus and consequent physiologic activation of the inspiratory muscles. The rat may be a useful model for further studies evaluating phrenic motoneuron physiology.