Intraspinal microstimulation and diaphragm activation after cervical spinal cord injury
| Autor: | Paul J. Reier, Elisa J. Gonzalez-Rothi, David D. Fuller, Savannah S Posgai, Lynne M. Mercier, Kristi A. Streeter, David M. Baekey, Alexander S. Poirier |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Physiology Diaphragm Biophysics Rats Sprague-Dawley Diaphragm function 03 medical and health sciences 0302 clinical medicine Animals Medicine Microstimulation Spinal Cord Injuries Analysis of Variance Electromyography business.industry General Neuroscience Cervical Cord Recovery of Function Anatomy musculoskeletal system Spinal cord Electric Stimulation Biomechanical Phenomena Rats Diaphragm (structural system) Disease Models Animal 030104 developmental biology medicine.anatomical_structure Spinal Cord Cervical spinal cord injury Female business 030217 neurology & neurosurgery Research Article |
| Zdroj: | Journal of Neurophysiology. 117:767-776 |
| ISSN: | 1522-1598 0022-3077 |
| DOI: | 10.1152/jn.00721.2016 |
| Popis: | Intraspinal microstimulation (ISMS) using implanted electrodes can evoke locomotor movements after spinal cord injury (SCI) but has not been explored in the context of respiratory motor output. An advantage over epidural and direct muscle stimulation is the potential of ISMS to selectively stimulate components of the spinal respiratory network. The present study tested the hypothesis that medullary respiratory activity could be used to trigger midcervical ISMS and diaphragm motor unit activation in rats with cervical SCI. Studies were conducted after acute (hours) and subacute (5–21 days) C2 hemisection (C2Hx) injury in adult rats. Inspiratory bursting in the genioglossus (tongue) muscle was used to trigger a 250-ms train stimulus (100 Hz, 100–200 μA) to the ventral C4 spinal cord, targeting the phrenic motor nucleus. After both acute and subacute injury, genioglossus EMG activity effectively triggered ISMS and activated diaphragm motor units during the inspiratory phase. The ISMS paradigm also evoked short-term potentiation of spontaneous inspiratory activity in the previously paralyzed hemidiaphragm (i.e., bursting persisting beyond the stimulus period) in ∼70% of the C2Hx animals. We conclude that medullary inspiratory output can be used to trigger cervical ISMS and diaphragm activity after SCI. Further refinement of this method may enable “closed-loop-like” ISMS approaches to sustain ventilation after severe SCI. NEW & NOTEWORTHY We examined the feasibility of using intraspinal microstimulation (ISMS) of the cervical spinal cord to evoke diaphragm activity ipsilateral to acute and subacute hemisection of the upper cervical spinal cord of the rat. This proof-of-concept study demonstrated the efficacy of diaphragm activation, using an upper airway respiratory EMG signal to trigger ISMS at the level of the ipsilesional phrenic nucleus during acute and advanced postinjury intervals. |
| Databáze: | OpenAIRE |
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