FLORIDA UNIV GAINESVILLE GAINESVILLE United States
The goal of this project is to determine whether electrical stimulation of the spinal cord can reduce respiratory dysfunctions occurring after mid-to-high cervical spinal cord injuries cSCI. Our primary focus is intraspinal microstimulation ISMS of the phrenic circuit using physiologically-appropriate, endogenous respiratory signals to trigger activation of the phrenic motoneuron PhMN pool following either cSCIs above or at the level of the phrenicnucleus in adult rats. A manuscript providing an important proof of concept demonstration has just been published. Our studies have established that ISMS at the level of the PhMN can effectively activate diaphragm motor units following high cSCI even beyond when stimulation ended. Another manuscript demonstrating independent verification of those findings is to be submitted by our colleagues at the University of Washington. Per comments from our proposals initial review, we also examined the efficacy of high frequency spinal stimulation. Our data indicate this approach is not effective at selectively activating inspiratory diaphragm phrenic motor units. A manuscript describing those results has been accepted pending revisions suggested by the reviewers. We are now testing chronic ISMS for improving breathing and promoting new synaptic connections following cSCI.