Sciatic nerve stimulation alleviates neuropathic pain and associated neuroinflammation in the dorsal root ganglia in a rodent model.

Background: Satellite glial cells (SGCs) in the dorsal root ganglia (DRG) play a pivotal role in the formation of neuropathic pain (NP). Sciatic nerve stimulation (SNS) neuromodulation was reported to alleviate NP and reduce neuroinflammation. However, the mechanisms underlying SNS in the DRG remain unclear.

Dynamic electrical stimulation enhances the recruitment of spinal interneurons by corticospinal input.

Highly varying patterns of electrostimulation (Dynamic Stimulation, DS) delivered to the dorsal cord through an epidural array with 18 independent electrodes transiently facilitate corticospinal motor responses, even after spinal injury. To partly unravel how corticospinal input are affected by DS, we introduced a corticospinal platform that allows selective cortical stimulation during the multisite acquisition of cord dorsum potentials (CDPs) and the simultaneous supply of DS. Firstly, the epidural interface was validated by the acquisition of the classical multisite distribution of CDPs and their input-output profile elicited by pulses delivered to peripheral nerves.

Spinal facilitation of descending motor input.

Highly varying patterns of electrostimulation (Dynamic Stimulation, DS) delivered to the dorsal cord through an epidural array with 18 independent electrodes transiently facilitate corticospinal motor responses, even after spinal injury. To partly unravel how corticospinal input are affected by DS, we introduced a corticospinal platform that allows selective cortical stimulation during the multisite acquisition of cord dorsum potentials (CDPs) and the simultaneous supply of DS. Firstly, the epidural interface was validated by the acquisition of the classical multisite distribution of CDPs on the dorsal cord and their input-output profile elicited by pulses delivered to peripheral nerves.

A Flexible Implant for Multi-Day Monitoring of Colon Segment Activity.

Monitoring of colon activity is currently limited to tethered systems like anorectal manometry. These systems have significant drawbacks, but fundamentally limit the observation time of colon activity, reducing the likelihood of detecting specific clinical events. While significant technological advancement has been directed to mobile sensor capsules, this work describes the development and feasibility of a stationary sensor for describing the coordinated activity between neighboring segments of the colon.

Electrical Sympathetic Neuromodulation Protects Bone Marrow Niche and Drives Hematopoietic Regeneration during Chemotherapy.

The sympathetic nervous system (SNS) of the bone marrow regulates the regeneration and mobilization of hematopoietic stem cells. Chemotherapy can damage bone marrow SNS, which impairs hematopoietic regeneration and aggravates hematologic toxicities. This leads to long-term bone marrow niche damage and increases mortality in patients undergoing chemotherapy.

Bio-impedance method to monitor colon motility response to direct distal colon stimulation in anesthetized pigs.

Electrical stimulation has been demonstrated as an alternative approach to alleviate intractable colonic motor disorders, whose effectiveness can be evaluated through colonic motility assessment. Various methods have been proposed to monitor the colonic motility and while each has contributed towards better understanding of colon motility, a significant limitation has been the spatial and temporal low-resolution colon motility data acquisition and analysis. This paper presents the study of employing bio-impedance characterization to monitor colonic motor activity.

Sciatic nerve stimulation alleviates acute neuropathic pain via modulation of neuroinflammation and descending pain inhibition in a rodent model.

Background: Neuropathic pain (NP) is characterized by abnormal activation of pain conducting pathways and manifests as mechanical allodynia and thermal hypersensitivity. Peripheral nerve stimulation is used for treatment of medically refractory chronic NP and has been shown to reduce neuroinflammation. However, whether sciatic nerve stimulation (SNS) is of therapeutic benefit to NP remains unclear.

An epidural stimulating interface unveils the intrinsic modulation of electrically motor evoked potentials in behaving rats.

In intact and spinal-injured anesthetized animals, stimulation levels that did not induce any visible muscle twitches were used to elicit motor evoked potentials (MEPs) of varying amplitude, reflecting the temporal and amplitude dynamics of the background excitability of spinal networks. To characterize the physiological excitability states of neuronal networks driving movement, we designed five experiments in awake rats chronically implanted with an epidural stimulating interface, with and without a spinal cord injury (SCI). First, an uninjured rat at rest underwent a series of single electrical pulses at sub-motor threshold intensity, which generated responses that were continuously recorded from flexor and extensor hindlimb muscles, showing an intrinsic patterned modulation of MEPs.

Crosstalk in Polymer Microelectrode Arrays.

Thin-film polymer microelectrode arrays (MEAs) facilitate the high-resolution neural recording with its superior mechanical compliance. However, the densely packed electrodes and interconnects along with the ultra-thin polymeric encapsulation/substrate layers give rise to non-negligible crosstalk, which could result in severe interference in the neural signal recording. Due to the lack of standardized characterization or modeling of crosstalk in neural electrode arrays, to date, crosstalk in polymer MEAs remains poorly understood.

A Biomimetic, SoC-Based Neural Stimulator for Novel Arbitrary-Waveform Stimulation Protocols.

Novel neural stimulation protocols mimicking biological signals and patterns have demonstrated significant advantages as compared to traditional protocols based on uniform periodic square pulses. At the same time, the treatments for neural disorders which employ such protocols require the stimulator to be integrated into miniaturized wearable devices or implantable neural prostheses. Unfortunately, most miniaturized stimulator designs show none or very limited ability to deliver biomimetic protocols due to the architecture of their control logic, which generates the waveform.

Stretchable, dynamic covalent polymers for soft, long-lived bioresorbable electronic stimulators designed to facilitate neuromuscular regeneration.

Bioresorbable electronic stimulators are of rapidly growing interest as unusual therapeutic platforms, i.e., bioelectronic medicines, for treating disease states, accelerating wound healing processes and eliminating infections.

Stability Performance Analysis of Various Packaging Materials and Coating Strategies for Chronic Neural Implants under Accelerated, Reactive Aging Tests.

Reliable packaging for implantable neural prosthetic devices in body fluids is a long-standing challenge for devices' chronic applications. This work studied the stability of Parylene C (PA), SiO, and SiN packages and coating strategies on tungsten wires using accelerated, reactive aging tests in three solutions: pH 7.4 phosphate-buffered saline (PBS), PBS + 30 mM HO, and PBS + 150 mM HO.

The effect of colonic tissue electrical stimulation and celiac branch of the abdominal vagus nerve neuromodulation on colonic motility in anesthetized pigs.

Background: Knowledge on optimal electrical stimulation (ES) modalities and region-specific functional effects of colonic neuromodulation is lacking. We aimed to map the regional colonic motility in response to ES of (a) the colonic tissue and (b) celiac branch of the abdominal vagus nerve (CBVN) in an anesthetized porcine model.

Methods: In male Yucatan pigs, direct ES (10 Hz, 2 ms, 15 mA) of proximal (pC), transverse (tC), or distal (dC) colon was done using planar flexible multi-electrode array panels and CBVN ES (2 Hz, 0.

Acute neuromodulation restores spinally-induced motor responses after severe spinal cord injury.

Epidural electrical spinal stimulation can facilitate recovery of volitional motor control in individuals that have been completely paralyzed for more than a year. We recently reported a novel neuromodulation method named Dynamic Stimulation (DS), which short-lastingly increased spinal excitability and generated a robust modulation of locomotor networks in fully-anesthetized intact adult rats. In the present study, we applied repetitive DS patterns to four lumbosacral segments acutely after a contusive injury at lumbar level.

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

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.

A Wireless Implantable System for Facilitating Gastrointestinal Motility.

Gastrointestinal (GI) electrical stimulation has been shown in several studies to be a potential treatment option for GI motility disorders. Despite the promising preliminary research progress, however, its clinical applicability and usability are still unknown and limited due to the lack of a miniaturized versatile implantable stimulator supporting the investigation of effective stimulation patterns for facilitating GI dysmotility. In this paper, we present a wireless implantable GI modulation system to fill this technology gap.

A Novel Biomimetic Stimulator System for Neural Implant.

Electrical stimulation using non-periodic biomimetic stimulation pattern has been shown to be effective in various critical biomedical applications. However, the existing programmable stimulators that support this protocol are non-portable and have architectures that are not translatable to wearable or implantable applications. In this work, we present a 32-channel neural stimulator system based on an implantable System-On-Chip (SoC) that addresses these technological challenges.

Propofol Anesthesia Increases Long-range Frontoparietal Corticocortical Interaction in the Oculomotor Circuit in Macaque Monkeys.

What We Already Know About This Topic: A decrease in frontoparietal functional connectivity has been demonstrated with multiple anesthetic agents, and this decrease has been proposed as a final common functional pathway to produce anesthesia.Two alternative measures of long-range cortical interaction are coherence and phase-amplitude coupling. Although phase-amplitude coupling within frontal cortex changes with propofol administration, the effects of propofol on phase-amplitude coupling between different cortical areas have not previously been reported.

Intestinal Electrical Stimulation to Increase the Rate of Peristalsis.

Background: Pediatric gastrointestinal motility disorders are a large and broad group. Some of these disorders have been effectively treated with electrical stimulation. The goal of our present study is to determine whether the rate of intestinal peristalsis can be increased with electrical stimulation.

A Wireless Platform to Support Pre-Clinical Trial of Neural Implant for Spinal Cord Injury.

The efficacy of many clinical applications of electrical stimulation is currently gauged only by patients' verbal feedback or through the use of an independent system, limiting physicians' ability to provide quality treatment. By integrating neural response recording into the system, though, more accurate measures of treatment effectiveness are possible. This paper presents a platform which enables wireless control of an implantable bioelectronic device which integrates functional electrical stimulation and simultaneous recording of neural activity for a wide range of potential applications including motor function prostheses for spinal cord injury, retinal prostheses, and treatments for various other conditions.

Improving EEG Source Localization with a Novel Regularization: Spatiotemporal Graph Total Variation (STGTV) Method.

Electroencephalography (EEG) source Iocalization aims at reconstructing the current density on the brain cortex from scalp EEG recordings. It of ten starts with a generative model that maps brain activity to the EEG recording, and then solves the inverse problem. Previously proposed method graph fractional-order total variation (gFOTV) is based on spatial regularization, and was shown superior to some other existing spatial-regularized methods in simulation tests.

Impact of Electrode Number on the Performance of High-Definition Transcranial Direct Current Stimulation (HD-tDCS).

Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation for treating brain disorders by applying constant current through scalp towards the targeted cortex regions. Precisely activating or inhibiting a specific area without interfering other parts in the brain is a challenge of tDCS. Recently high-definition tDCS (HD-tDCS) with optimization technique attracts a lot of attention due to the improved focality.

A Wireless Implant for Gastrointestinal Motility Disorders.

Implantable functional electrical stimulation (IFES) has demonstrated its effectiveness as an alternative treatment option for diseases incurable pharmaceutically (e.g., retinal prosthesis, cochlear implant, spinal cord implant for pain relief).

Transparent arrays of bilayer-nanomesh microelectrodes for simultaneous electrophysiology and two-photon imaging in the brain.

Transparent microelectrode arrays have emerged as increasingly important tools for neuroscience by allowing simultaneous coupling of big and time-resolved electrophysiology data with optically measured, spatially and type resolved single neuron activity. Scaling down transparent electrodes to the length scale of a single neuron is challenging since conventional transparent conductors are limited by their capacitive electrode/electrolyte interface. In this study, we establish transparent microelectrode arrays with high performance, great biocompatibility, and comprehensive in vivo validations from a recently developed, bilayer-nanomesh material composite, where a metal layer and a low-impedance faradaic interfacial layer are stacked reliably together in a same transparent nanomesh pattern.