Effect of Low Intensity Magnetic Field Stimulation on Calcium-Mediated Cytotoxicity After Mild Spinal Cord Contusion Injury in Rats

Cortical intermittent theta burst stimulation on gait pathomechanics and urinary tract dysfunction in incomplete spinal cord injury patients: Protocol for a randomized controlled trial

Gait impairment and neurogenic bladder are co-existing common findings in incomplete spinal cord injury (iSCI). Repetitive transcranial magnetic stimulation (rTMS), evident to be a promising strategy adjunct to physical rehabilitation to regain normal ambulation in SCI. However, there is a need to evaluate the role of Intermittent theta burst stimulation (iTBS), a type of patterned rTMS in restoring gait and neurogenic bladder in SCI patients. The aim of the present study is to quantify the effect of iTBS on spatiotemporal, kinetic, and kinematic parameters of gait and neurogenic bladder dyssynergia in iSCI. After maturing all exclusion and inclusion criteria, thirty iSCI patients will be randomly divided into three groups: Group-A (sham), Group-B (active rTMS) and Group-C (active iTBS). Each group will receive stimulation adjunct to physical rehabilitation for 2 weeks. All patients will undergo gait analysis, as well assessment of bladder, electrophysiological, neurological, functional, and psychosocial parameters. All parameters will be assessed at baseline and 6th week (1st follow-up). Parameters except urodynamics and gait analysis will also be assessed after the end of the 2 weeks of the intervention (post-intervention) and at 12th week (2nd follow-up). Appropriate statistical analysis will be done using various parametric and non-parametric tests based on results.

Delivery of TGFβ3 from Magnetically Responsive Coaxial Fibers Reduces Spinal Cord Astrocyte Reactivity In Vitro

A spinal cord injury (SCI) compresses the spinal cord, killing neurons and glia at the injury site and resulting in prolonged inflammation and scarring that prevents regeneration. Astrocytes, the main glia in the spinal cord, become reactive following SCI and contribute to adverse outcomes. The anti-inflammatory cytokine transforming growth factor beta 3 (TGFβ3) has been shown to mitigate astrocyte reactivity; however, the effects of prolonged TGFβ3 exposure on reactive astrocyte phenotype have not yet been explored. This study investigates whether magnetic core-shell electrospun fibers can be used to alter the release rate of TGFβ3 using externally applied magnetic fields, with the eventual application of tailored drug delivery based on SCI severity. Magnetic core-shell fibers are fabricated by incorporating superparamagnetic iron oxide nanoparticles (SPIONs) into the shell and TGFβ3 into the core solution for coaxial electrospinning. Magnetic field stimulation increased the release rate of TGFβ3 from the fibers by 25% over 7 days and released TGFβ3 reduced gene expression of key astrocyte reactivity markers by at least twofold. This is the first study to magnetically deliver bioactive proteins from magnetic fibers and to assess the effect of sustained release of TGFβ3 on reactive astrocyte phenotype.

Omega-conotoxin MVIIA reduces neuropathic pain after spinal cord injury by inhibiting N-type voltage-dependent calcium channels on spinal dorsal horn

Spinal cord injury (SCI) leads to the development of neuropathic pain. Although a multitude of pathological processes contribute to SCI-induced pain, excessive intracellular calcium accumulation and voltage-gated calcium-channel upregulation play critical roles in SCI-induced pain. However, the role of calcium-channel blockers in SCI-induced pain is unknown. Omega-conotoxin MVIIA (MVIIA) is a calcium-channel blocker that selectively inhibits N-type voltage-dependent calcium channels and demonstrates neuroprotective effects. Therefore, we investigated spinal analgesic actions and cellular mechanisms underlying the analgesic effects of MVIIA in SCI. We used SCI-induced pain model rats and conducted behavioral tests, immunohistochemical analyses, and electrophysiological experiments (in vitro whole-cell patch-clamp recording and in vivo extracellular recording). A behavior study suggested intrathecal MVIIA administration in the acute phase after SCI induced analgesia for mechanical allodynia. Immunohistochemical experiments and in vivo extracellular recordings suggested that MVIIA induces analgesia in SCI-induced pain by directly inhibiting neuronal activity in the superficial spinal dorsal horn. In vitro whole-cell patch-clamp recording showed that MVIIA inhibits presynaptic N-type voltage-dependent calcium channels expressed on primary afferent Aδ-and C-fiber terminals and suppresses the presynaptic glutamate release from substantia gelatinosa in the spinal dorsal horn. In conclusion, MVIIA administration in the acute phase after SCI may induce analgesia in SCI-induced pain by inhibiting N-type voltage-dependent calcium channels on Aδ-and C-fiber terminals in the spinal dorsal horn, resulting in decreased neuronal excitability enhanced by SCI-induced pain.

Spinal cord injury: molecular mechanisms and therapeutic interventions

Spinal cord injury (SCI) remains a severe condition with an extremely high disability rate. The challenges of SCI repair include its complex pathological mechanisms and the difficulties of neural regeneration in the central nervous system. In the past few decades, researchers have attempted to completely elucidate the pathological mechanism of SCI and identify effective strategies to promote axon regeneration and neural circuit remodeling, but the results have not been ideal. Recently, new pathological mechanisms of SCI, especially the interactions between immune and neural cell responses, have been revealed by single-cell sequencing and spatial transcriptome analysis. With the development of bioactive materials and stem cells, more attention has been focused on forming intermediate neural networks to promote neural regeneration and neural circuit reconstruction than on promoting axonal regeneration in the corticospinal tract. Furthermore, technologies to control physical parameters such as electricity, magnetism and ultrasound have been constantly innovated and applied in neural cell fate regulation. Among these advanced novel strategies and technologies, stem cell therapy, biomaterial transplantation, and electromagnetic stimulation have entered into the stage of clinical trials, and some of them have already been applied in clinical treatment. In this review, we outline the overall epidemiology and pathophysiology of SCI, expound on the latest research progress related to neural regeneration and circuit reconstruction in detail, and propose future directions for SCI repair and clinical applications.

Electromagnetic Field Stimulation Attenuates Phasic Nociception after Complete Spinal Cord Injury in Rats

Traumatic spinal cord injury (SCI) is one of the most incapacitating pathologies, leading to huge rehabilitation challenges besides a social-economic burden on SCI patients and their families. There is no complete curative treatment available so far. Non-invasive and patient-friendly use of extremely low-frequency electromagnetic field stimulation (EMF) has emerged as a therapeutic and rehabilitation option. In this study, we tested whole-body EMF stimulation on thoracic complete SCI-induced nociception including sensorimotor deficits in rats. The EMF application significantly attenuated hyperalgesia and allodynia to thermal, electrical, and chemical stimuli from 6 weeks onwards as well as restoration of spinal reflexes, viz., H-reflex and nociceptive flexion reflex at the study endpoint (week 8). Besides, massively increased glutamate at the SCI injury site was observed in SCI rats with no treatment, which was also attenuated significantly by EMF stimulation. Spinal cord histology of the injury area showed a decrease in lesion volume and glial population in the EMF-stimulated rats. These findings indicate the beneficial role of EMF stimulation after thoracic complete SCI in adult male rats and, thereby, a beneficial patient-friendly rehabilitation tool.