The purpose of this Mentored Research Scientist Development Award is to prepare the candidate for a successful long-term career in medical rehabilitative research. The candidate will receive primary sponsorship from a senior-level scientist who will provide the candidate with a period of intensive, focused training in the areas of motor cortical neurophysiology, motor cortical plasticity following stroke, and the use of transcranial magnetic stimulation as a research tool to measure cortical excitability. The purpose of the research proposed here is to determine mechanisms of bilateral leg control in individuals with post stroke hemi paresis;specifically, to determine the effects of the sensorimotor state of one leg on the motor behavior of the opposite leg. Three studies will be undertaken to determine: 1) does damage to the motor cortex cause specific deficits in bilateral more than unilateral cyclical ankle movements? 2) to what extent do ipsilateral uncrossed corticospinal pathways contribute to unilateral and bilateral cyclical ankle movements in individuals with motor cortical stroke? and 3) does damage to the motor cortex impair bilateral leg motor responses to a novel unilateral perturbation during walking? To answer these questions, 3-D movement kinematics and electromyography will be recorded from subjects with hemi paresis caused by motor cortical stroke and healthy age- and gender-matched control subjects performing ankle movement tasks and walking. Results will help explain the specific function of the motor cortex and corticospinal pathway and will provide a basis for the development of novel rehabilitation techniques to recover normal locomotor's function in individuals with post-stroke hemi paresis. The mentorship provided in this plan will help direct the candidate toward independence as an investigator and lend significant progress toward the candidate's long-term research goal of understanding interlimb coordination during human locomotion and mechanisms for recovery of locomotor's function following neurological damage.

Public Health Relevance

This research will have broad impact on public health, as stroke is a leading cause of long-term disability and leaves many of its victims unable to walk without assistance (AHA 2005). Findings from these studies are expected to help lead to the development of new treatments aimed at stroke rehabilitation generally and gait recovery specifically.

National Institute of Health (NIH)
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Research Scientist Development Award - Research & Training (K01)
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Special Emphasis Panel (ZHD1-DSR-T (04))
Program Officer
Ansel, Beth
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University of Iowa
Other Health Professions
Schools of Medicine
Iowa City
United States
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Savin, Douglas N; Morton, Susanne M; Whitall, Jill (2014) Generalization of improved step length symmetry from treadmill to overground walking in persons with stroke and hemiparesis. Clin Neurophysiol 125:1012-20
Savin, Douglas N; Tseng, Shih-Chiao; Whitall, Jill et al. (2013) Poststroke hemiparesis impairs the rate but not magnitude of adaptation of spatial and temporal locomotor features. Neurorehabil Neural Repair 27:24-34
Vasudevan, Erin V L; Torres-Oviedo, Gelsy; Morton, Susanne M et al. (2011) Younger is not always better: development of locomotor adaptation from childhood to adulthood. J Neurosci 31:3055-65
Harris-Love, Michelle L; Morton, Susanne M; Perez, Monica A et al. (2011) Mechanisms of short-term training-induced reaching improvement in severely hemiparetic stroke patients: a TMS study. Neurorehabil Neural Repair 25:398-411
Morton, Susanne M; Tseng, Ya-Weng; Zackowski, Kathleen M et al. (2010) Longitudinal tracking of gait and balance impairments in cerebellar disease. Mov Disord 25:1944-52
Tseng, Shih-Chiao; Stanhope, Steven J; Morton, Susanne M (2010) Visuomotor adaptation of voluntary step initiation in older adults. Gait Posture 31:180-4
Savin, Douglas N; Tseng, Shih-Chiao; Morton, Susanne M (2010) Bilateral adaptation during locomotion following a unilaterally applied resistance to swing in nondisabled adults. J Neurophysiol 104:3600-11
Tseng, Shih-Chiao; Morton, Susanne M (2010) Impaired interlimb coordination of voluntary leg movements in poststroke hemiparesis. J Neurophysiol 104:248-57
Reisman, Darcy S; Bastian, Amy J; Morton, Susanne M (2010) Neurophysiologic and rehabilitation insights from the split-belt and other locomotor adaptation paradigms. Phys Ther 90:187-95
Morton, Susanne M; Bastian, Amy J (2009) Can rehabilitation help ataxia? Neurology 73:1818-9

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