Giuliano Taccola1, Parag Gad2, Stanislav Culaclii3, Ronaldo M Ichiyama4, Wentai Liu5, V Reggie Edgerton6. 1. Department of Integrative Biology and Physiology, University of California, Los Angeles, CA, 90095, USA; Neuroscience Department, International School for Advanced Studies (SISSA), Bonomea 265, Trieste, Italy; School of Biomedical Sciences, University of Leeds, Leeds, LS2 9JT, UK. Electronic address: taccola@sissa.it. 2. Department of Integrative Biology and Physiology, University of California, Los Angeles, CA, 90095, USA. 3. Department of Bioengineering, University of California, Los Angeles, CA, 90095, USA. 4. School of Biomedical Sciences, University of Leeds, Leeds, LS2 9JT, UK. 5. Department of Bioengineering, University of California, Los Angeles, CA, 90095, USA; Brain Research Institute, University of California, Los Angeles, CA, 90095, USA. 6. Department of Integrative Biology and Physiology, University of California, Los Angeles, CA, 90095, USA; Department of Neurobiology, University of California, Los Angeles, CA, 90095, USA; Department of Neurosurgery, University of California, Los Angeles, CA, 90095, USA; Brain Research Institute, University of California, Los Angeles, CA, 90095, USA; The Centre for Neuroscience and Regenerative Medicine, Faculty of Science, University of Technology Sydney, Ultimo, 2007, NSW, Australia; Institut Guttmann, Hospital de Neurorehabilitació, Institut Universitari Adscrit a La Universitat Autònoma de Barcelona, Barcelona, 08916, Badalona, Spain. Electronic address: vre@ucla.edu.
Abstract
BACKGROUND: Potentiation of synaptic activity in spinal networks is reflected in the magnitude of modulation of motor responses evoked by spinal and cortical input. After spinal cord injury, motor evoked responses can be facilitated by pairing cortical and peripheral nerve stimuli. OBJECTIVE: To facilitate synaptic potentiation of cortico-spinal input with epidural electrical stimulation, we designed a novel neuromodulation method called dynamic stimulation (DS), using patterns derived from hind limb EMG signal during stepping. METHODS: DS was applied dorsally to the lumbar enlargement through a high-density epidural array composed of independent platinum-based micro-electrodes. RESULTS: In fully anesthetized intact adult rats, at the interface array/spinal cord, the temporal and spatial features of DS neuromodulation affected the entire lumbosacral network, particularly the most rostral and caudal segments covered by the array. DS induced a transient (at least 1 min) increase in spinal cord excitability and, compared to tonic stimulation, generated a more robust potentiation of the motor output evoked by single pulses applied to the spinal cord. When sub-threshold pulses were selectively applied to a cortical motor area, EMG responses from the contralateral leg were facilitated by the delivery of DS to the lumbosacral cord. Finally, based on motor-evoked responses, DS was linked to a greater amplitude of motor output shortly after a calibrated spinal cord contusion. CONCLUSION: Compared to traditional tonic waveforms, DS amplifies both spinal and cortico-spinal input aimed at spinal networks, thus significantly increasing the potential and accelerating the rate of functional recovery after a severe spinal lesion.
BACKGROUND: Potentiation of synaptic activity in spinal networks is reflected in the magnitude of modulation of motor responses evoked by spinal and cortical input. After spinal cord injury, motor evoked responses can be facilitated by pairing cortical and peripheral nerve stimuli. OBJECTIVE: To facilitate synaptic potentiation of cortico-spinal input with epidural electrical stimulation, we designed a novel neuromodulation method called dynamic stimulation (DS), using patterns derived from hind limb EMG signal during stepping. METHODS:DS was applied dorsally to the lumbar enlargement through a high-density epidural array composed of independent platinum-based micro-electrodes. RESULTS: In fully anesthetized intact adult rats, at the interface array/spinal cord, the temporal and spatial features of DS neuromodulation affected the entire lumbosacral network, particularly the most rostral and caudal segments covered by the array. DS induced a transient (at least 1 min) increase in spinal cord excitability and, compared to tonic stimulation, generated a more robust potentiation of the motor output evoked by single pulses applied to the spinal cord. When sub-threshold pulses were selectively applied to a cortical motor area, EMG responses from the contralateral leg were facilitated by the delivery of DS to the lumbosacral cord. Finally, based on motor-evoked responses, DS was linked to a greater amplitude of motor output shortly after a calibrated spinal cord contusion. CONCLUSION: Compared to traditional tonic waveforms, DS amplifies both spinal and cortico-spinal input aimed at spinal networks, thus significantly increasing the potential and accelerating the rate of functional recovery after a severe spinal lesion.
Authors: Clare Taylor; Conor McHugh; David Mockler; Conor Minogue; Richard B Reilly; Neil Fleming Journal: PLoS One Date: 2021-11-18 Impact factor: 3.240
Authors: Pallavi Asthana; Gajendra Kumar; Lukasz M Milanowski; Ngan Pan Bennett Au; Siu Chung Chan; Jianpan Huang; Hemin Feng; Kin Ming Kwan; Jufang He; Kannie Wai Yan Chan; Zbigniew K Wszolek; Chi Him Eddie Ma Journal: NPJ Regen Med Date: 2022-09-05