Two Distinct Stimulus Frequencies Delivered Simultaneously at Low Intensity Generate Robust Locomotor Patterns

Dose, Francesco; Taccola, Giuliano

doi:10.1111/ner.12402

Cited by 6 publications

(10 citation statements)

References 59 publications

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“…Albeit variations in frequency of stereotyped trains of pulses within a relatively broad range (1-25 Hz) does not affect number (nor periodicity) of locomotor cycles [147], stimulation with trains of distinct pairs of frequencies, even simultaneously delivered to different DRs, activates longer episodes of FL [150]. This suggests that, rather than the selection of a specific frequency, optimal DR electrostimulation to evoke FL must provide a minimum level of input range variability.…”

Section: Selective Electrostimulation Of Dorsal Roots Triggers Locomomentioning

confidence: 99%

“…In these preparations, electrical stimulation with stereotyped trains of square impulses triggered brief episodes of electrical oscillations, alternating between flexor and extensor motor pools on both sides of the cord (fictive locomotion rhythm, FL; [25]), when selectively delivered through tight fitting electrodes to either DRs [147] or sacrocaudal afferents [148]. In addition, activation of multiple DRs with staggered pulses [149,150] effectively generated FL, indicating a multi-segmental convergence of afferent inputs on neuronal circuits during electrical spinal cord stimulation, as also reported in both in vivo animals [151] and in humans [100,152].…”

Section: Selective Electrostimulation Of Dorsal Roots Triggers Locomomentioning

confidence: 99%

“…noisy) patterns, obtained by sampling biosignals corresponding to rhythmic motor patterns in vitro or in vivo, from either a ventral root (VR, Fig. 1B), a muscle, or a single motoneuron [131,150,170,173,174]. The clear advantage of this approach relies on stimulation strength, which, unlike canonical electrostimulation, is much lower than the minimum one required to induce a reflex response (i.e., subthreshold).…”

Section: Innovative Protocols Of Electrostimulation Exploit the Intrimentioning

confidence: 99%

“…These results indicate that input able to optimally trigger the CPG must contain both the low frequency component of rhythmic motor tasks and the high frequency spectral density of motor-related biosignals. As a result, effectiveness of noisy waveforms might be linked to the relative contribution of such distinct stimulus frequencies particularly efficient in activating frequency-dependent CPG elements [150]. Moreover, variability in the amplitude of the stimulating patterns might play a crucial role reminiscent of the control over sacral network output, using amplitude-modulated signals delivered to the peripheral nerve [171,172].…”

Section: Innovative Protocols Of Electrostimulation Exploit the Intrimentioning

confidence: 99%

“…As a result, we can carefully determine the efficacy of the different protocols of stimulation, by quantifying the number of FL oscillations or by assessing the minimum duration of stimulation required to induce an episode of FL. For example, the most selective protocols available in vitro are efficient even when delivered for periods as short as 500 ms [150].…”

Section: Strengths and Limitations Of The In Vitro Approachmentioning

confidence: 99%

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Multilevel Analysis of Locomotion in Immature Preparations Suggests Innovative Strategies to Reactivate Stepping after Spinal Cord Injury

Brumley

Guertin

Taccola

2017

CPD

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Locomotion is one of the most complex motor behaviors. Locomotor patterns change during early life, reflecting development of numerous peripheral and hierarchically organized central structures. Among them, the spinal cord is of particular interest since it houses the central pattern generator (CPG) for locomotion. This main command center is capable of eliciting and coordinating complex series of rhythmic neural signals sent to motoneurons and to corresponding target-muscles for basic locomotor activity. For a long-time, the CPG has been considered a black box. In recent years, complementary insights from in vitro and in vivo animal models have contributed significantly to a better understanding of its constituents, properties and ways to recover locomotion after a spinal cord injury (SCI). This review discusses key findings made by comparing the results of in vitro isolated spinal cord preparations and spinal-transected in vivo models from neonatal animals. Pharmacological, electrical, and sensory stimulation approaches largely used to further understand CPG function may also soon become therapeutic tools for potent CPG reactivation and locomotor movement induction in persons with SCI or developmental neuromuscular disorder.

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Section: Selective Electrostimulation Of Dorsal Roots Triggers Locomomentioning

confidence: 99%

Section: Selective Electrostimulation Of Dorsal Roots Triggers Locomomentioning

confidence: 99%

Section: Innovative Protocols Of Electrostimulation Exploit the Intrimentioning

confidence: 99%

Section: Innovative Protocols Of Electrostimulation Exploit the Intrimentioning

confidence: 99%

Section: Strengths and Limitations Of The In Vitro Approachmentioning

confidence: 99%

See 3 more Smart Citations

Multilevel Analysis of Locomotion in Immature Preparations Suggests Innovative Strategies to Reactivate Stepping after Spinal Cord Injury

Brumley

Guertin

Taccola

2017

CPD

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View full text Add to dashboard Cite

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Suprapontine Structures Modulate Brainstem and Spinal Networks

et al. 2023

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Several spinal motor output and essential rhythmic behaviors are controlled by supraspinal structures, although their contribution to neuronal networks for respiration and locomotion at birth still requires better characterization. As preparations of isolated brainstem and spinal networks only focus on local circuitry, we introduced the in vitro central nervous system (CNS) from neonatal rodents to simultaneously record a stable respiratory rhythm from both cervical and lumbar ventral roots (VRs).Electrical pulses supplied to multiple sites of brainstem evoked distinct VR responses with staggered onset in the rostro-caudal direction. Stimulation of ventrolateral medulla (VLM) resulted in higher events from homolateral VRs. Stimulating a lumbar dorsal root (DR) elicited responses even from cervical VRs, albeit small and delayed, confirming functional ascending pathways. Oximetric assessments detected optimal oxygen levels on brainstem and cortical surfaces, and histological analysis of internal brain structures indicated preserved neuron viability without astrogliosis. Serial ablations showed precollicular decerebration reducing respiratory burst duration and frequency and diminishing the area of lumbar DR and VR potentials elicited by DR stimulation, while pontobulbar transection increased the frequency and duration of respiratory bursts. Keeping legs attached allows for expressing a respiratory rhythm during hindlimb stimulation. Trains of pulses evoked episodes of fictive locomotion (FL) when delivered to VLM or to a DR, the latter with a slightly better FL than in isolated cords.In summary, suprapontine centers regulate spontaneous respiratory rhythms, as well as electrically evoked reflexes and spinal network activity. The current approach contributes to clarifying modulatory brain influences on the brainstem and spinal microcircuits during development. Graphical Abstract Novel preparation of the entire isolated CNS from newborn rats unveils suprapontine modulation on brainstem and spinal networks. Preparation views (A) with and without legs attached (B). Successful fictive respiration occurs with fast dissection from P0-P2 rats (C). Decerebration speeds up respiratory rhythm (D) and reduces spinal reflexes derived from both ventral and dorsal lumbar roots (E).

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Using EMG to deliver lumbar dynamic electrical stimulation to facilitate cortico-spinal excitability

et al. 2020

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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.

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Two Distinct Stimulus Frequencies Delivered Simultaneously at Low Intensity Generate Robust Locomotor Patterns

Cited by 6 publications

References 59 publications

Multilevel Analysis of Locomotion in Immature Preparations Suggests Innovative Strategies to Reactivate Stepping after Spinal Cord Injury

Multilevel Analysis of Locomotion in Immature Preparations Suggests Innovative Strategies to Reactivate Stepping after Spinal Cord Injury

Suprapontine Structures Modulate Brainstem and Spinal Networks

Using EMG to deliver lumbar dynamic electrical stimulation to facilitate cortico-spinal excitability

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