Poster abstracts
Poster number 99 submitted by Timothy Faw
Training Persistent Motor Deficits Improves Locomotion After SCI
Timothy D. Faw (Neuroscience Graduate Program, The Ohio State University), Christopher N. Hansen, Lesley C. Fisher, Rochelle J Deibert, John A. Buford (School of Health and Rehabilitation Sciences, The Ohio State University), Lise C. Worthen-Chaudhari (Physical Medicine and Rehabilitation, The Ohio State University), James P. Schmiedeler (Department of Aerospace and Mechanical Engineering, Notre Dame University), James W. Grau (Behavioral and Cellular Neuroscience, Texas A&M University), D. Michele Basso (School of Health and Rehabilitation Sciences, The Ohio State University)
Abstract:
Eccentric motor control is required for skilled motor performance. Precise matching of motor and sensory input enables controlled muscle lengthening, important for weight acceptance and efficient forward progression during walking. Here, we show that incomplete spinal cord injury (SCI) causes eccentric deficits in humans and rodents that persist even after intensive rehabilitation. Importantly, novel interventions for SCI could save up to $400 billion in lifetime costs, if they effectively reduce deficits and restore motor function. Eccentric-focused, downhill (DH) treadmill training is a novel, more challenging paradigm that magnifies spared sensorimotor activation during locomotion. Locomotor kinematics identified persistent deficits in humans (n=3; SCI n=2, Uninjured n=1) and rodents (n=22; SCI n=12, Naïve n=10). We then tested whether DH training mitigates locomotor deficits and improves recovery after SCI in rodents. Rats had severe T8 SCI then traditional flat (n=6) or DH (n=6) treadmill training 34-41 days post injury. Naïve, flat, and DH groups underwent kinematics and electromyography (EMG) for locomotion and instrumental learning for spinal cord neuroplasticity. Because the inflammatory microenvironment of the lumbar cord after SCI can negatively affect locomotor recovery, we performed ELISA protein quantification after training in sister groups (Flat, n=3; DH, n=3; SCI Unexercised, n=9). Joint coordination during weight acceptance revealed loss of eccentric control between the knee and ankle in humans and rodents with SCI. Importantly, DH but not flat training restored intralimb coordination and locomotor function by decreasing trunk instability (p<.05) and toe drags (p<.05), both common after human SCI. Improvements were supported by normalized EMG timing and amplitude of key hindlimb muscles (semitendinosus, tibialis anterior) active during eccentric phases of gait. DH but not flat training induced adaptive neuroplasticity and spinal learning (p<.05) in the cord while reducing inflammatory cytokines, TNF&alpha (p<.05) and IL-1&beta (p<.05). Importantly, using task-specific, eccentric-focused rehabilitation in rodents is effective for improving locomotor function in rodents and is currently underway in people with SCI.
References:
Hansen et al. (2016) Frontiers in Neural Circuits, 10:11.
Keywords: Spinal Cord Injury, Locomotion, Eccentric