Our research program is focused on understanding the role of respiratory afferents in cardiorespiratory control, the mechanisms by which afferents induce respiratory motor plasticity, and the therapeutic potential of respiratory afferent activation after cervical spinal cord injury. Our laboratory uses a multi-disciplinary approach including behavioral studies, neurophysiological preparations, and molecular techniques to investigate the functional significance and therapeutic potential of respiratory afferent activation, with the ultimate goal of identifying novel rehabilitative strategies to improve cardiorespiratory control following cervical spinal cord injury
Phrenic Afferents and Respiratory Motor Plasticity
Sensory input from the diaphragm can alter cardiorespiratory output. However, the impact of phrenic afferent activation on respiratory motor output over longer time scales remains largely unexplored. Our studies explore how repeated activation of phrenic afferents may induce long-lasting changes in phrenic motor output.
Photo: Example of a phrenic afferent induced respiratory motor plasticity.
Phrenic Afferents and Interneurons
Recent work has shown that diaphragm afferents project to an intraneuronal network within the cervical spinal cord and alter discharge. Since spinal interneurons have the potential to influence respiratory motor output, we are interested in how respiratory afferent activation modulates interneuron activity.
Photo: Histograms of discharge rate of one spinal interneuron before (green bars) and after (purple bars) brief phrenic nerve stimulation showing an increase in spinal interneuron discharge rate post-stimulation.
Phrenic Afferents and Spinal Cord Injury
Cervical spinal cord injury disrupts descending drive to the primary inspiratory muscle, the diaphragm, and results in profound breathing impairments. Individuals with cervical spinal cord injury are also at the highest risk for developing aberrant sympathetically driven cardiovascular responses. Respiratory afferents are known to influence both respiratory motor output and cardiovascular control. Our studies explore the therapeutic potential of respiratory afferent activation after cervical spinal cord injury.
Photo: An example of the recording equipment utilized with our chronic studies.