title: Spinal metaplasticity in respiratory motor control.
abstract: A hallmark feature of the neural system controlling breathing is its ability to exhibit plasticity. Less appreciated is the ability to exhibit metaplasticity, a change in the capacity to express plasticity (i.e., "plastic plasticity"). Recent advances in our understanding of cellular mechanisms giving rise to respiratory motor plasticity lay the groundwork for (ongoing) investigations of metaplasticity. This detailed understanding of respiratory metaplasticity will be essential as we harness metaplasticity to restore breathing capacity in clinical disorders that compromise breathing, such as cervical spinal injury, motor neuron disease and other neuromuscular diseases. In this brief review, we discuss key examples of metaplasticity in respiratory motor control, and our current understanding of mechanisms giving rise to spinal plasticity and metaplasticity in phrenic motor output; particularly after pre-conditioning with intermittent hypoxia. Progress in this area has led to the realization that similar mechanisms are operative in other spinal motor networks, including those governing limb movement. Further, these mechanisms can be harnessed to restore respiratory and non-respiratory motor function after spinal injury.
authors.affiliation: Department of Comparative Biosciences, University of Wisconsin-Madison Madison, WI, USA.
authors.forename: Daryl P
authors.initials: DP
authors.lastname: Fields
authors.affiliation: Department of Comparative Biosciences, University of Wisconsin-Madison Madison, WI, USA.
authors.forename: Gordon S
authors.initials: GS
authors.lastname: Mitchell
mesh_terms: D000818:Animals; D006801:Humans; D009473:Neuronal Plasticity / Q000502:physiology; D012119:Respiration; D013116:Spinal Cord / Q000502:physiology*
keywords: intermittent hypoxia; metaplasticity; motor neuron; phrenic motor neuron; respiratory control; respiratory plasticity; spinal cord