Physiological evidence for specificity of synaptic connections between individual sensory and motor neurons in the brachial spinal cord of the bullfrog

AbstractRespiratory insufficiency is a leading cause of death due to drug overdose or neuromuscular disease. We hypothesized that a stimulation paradigm using temporal interference (TI) could restore breathing in such conditions. Following opioid overdose in rats, two high frequency (5000 Hz and 5001 Hz), low amplitude waveforms delivered via intramuscular wires in the neck immediately activated the diaphragm and restored ventilation in phase with waveform offset (1 Hz or 60 breaths/min). Following cervical spinal cord injury (SCI), TI stimulation via dorsally placed epidural electrodes uni- or bilaterally activated the diaphragm depending on current and electrode position. In silico modeling indicated that an interferential signal in the ventral spinal cord predicted the evoked response (left versus right diaphragm) and current-ratio-based steering. We conclude that TI stimulation can activate spinal motor neurons after SCI and prevent fatal apnea during drug overdose by restoring ventilation with minimally invasive electrodes.

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Single-cell transcriptomic analysis of the adult mouse spinal cord reveals molecular diversity of autonomic and skeletal motor neurons

Nature Neuroscience ◽

10.1038/s41593-020-00795-0 ◽

2021 ◽

Vol 24 (4) ◽

pp. 572-583 ◽

Cited By ~ 1

Author(s):

Jacob A. Blum ◽

Sandy Klemm ◽

Jennifer L. Shadrach ◽

Kevin A. Guttenplan ◽

Lisa Nakayama ◽

...

Keyword(s):

Spinal Cord ◽

Single Cell ◽

Motor Neurons ◽

Molecular Diversity ◽

Adult Mouse ◽

Transcriptomic Analysis ◽

Mouse Spinal Cord

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CD157 in bone marrow mesenchymal stem cells mediates mitochondrial production and transfer to improve neuronal apoptosis and functional recovery after spinal cord injury

Stem Cell Research & Therapy ◽

10.1186/s13287-021-02305-w ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Jing Li ◽

Heyangzi Li ◽

Simin Cai ◽

Shi Bai ◽

Huabo Cai ◽

...

Keyword(s):

Spinal Cord ◽

Stem Cells ◽

Bone Marrow ◽

Spinal Cord Injury ◽

Mesenchymal Stem Cells ◽

Motor Neurons ◽

Functional Recovery ◽

Mitochondrial Transfer ◽

Cord Injury ◽

Marrow Mesenchymal Stem Cells

Abstract Background Recent studies demonstrated that autologous mitochondria derived from bone marrow mesenchymal stem cells (BMSCs) might be valuable in the treatment of spinal cord injury (SCI). However, the mechanisms of mitochondrial transfer from BMSCs to injured neurons are not fully understood. Methods We modified BMSCs by CD157, a cell surface molecule as a potential regulator mitochondria transfer, then transplanted to SCI rats and co-cultured with OGD injured VSC4.1 motor neuron. We detected extracellular mitochondrial particles derived from BMSCs by transmission electron microscope and measured the CD157/cyclic ADP-ribose signaling pathway-related protein expression by immunohistochemistry and Western blotting assay. The CD157 ADPR-cyclase activity and Fluo-4 AM was used to detect the Ca2+ signal. All data were expressed as mean ± SEM. Statistical analysis was analyzed by GraphPad Prism 6 software. Unpaired t-test was used for the analysis of two groups. Multiple comparisons were evaluated by one-way ANOVA or two-way ANOVA. Results CD157 on BMSCs was upregulated when co-cultured with injured VSC4.1 motor neurons. Upregulation of CD157 on BMSCs could raise the transfer extracellular mitochondria particles to VSC4.1 motor neurons, gradually regenerate the axon of VSC4.1 motor neuron and reduce the cell apoptosis. Transplantation of CD157-modified BMSCs at the injured sites could significantly improve the functional recovery, axon regeneration, and neuron apoptosis in SCI rats. The level of Ca2+ in CD157-modified BMSCs dramatically increased when objected to high concentration cADPR, ATP content, and MMP of BMSCs also increased. Conclusion The present results suggested that CD157 can regulate the production and transfer of BMSC-derived extracellular mitochondrial particles, enriching the mechanism of the extracellular mitochondrial transfer in BMSCs transplantation and providing a novel strategy to improve the stem cell treatment on SCI.

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Muscle-conditioned media and cAMP promote survival and neurite outgrowth of adult spinal cord motor neurons

Experimental Neurology ◽

10.1016/j.expneurol.2009.09.003 ◽

2009 ◽

Vol 220 (2) ◽

pp. 303-315 ◽

Cited By ~ 17

Author(s):

Jose V. Montoya G. ◽

Jhon Jairo Sutachan ◽

Wai Si Chan ◽

Alexandra Sideris ◽

Thomas J.J. Blanck ◽

...

Keyword(s):

Spinal Cord ◽

Neurite Outgrowth ◽

Motor Neurons ◽

Conditioned Media ◽

Adult Spinal Cord

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RBM45 Modulates the Antioxidant Response in Amyotrophic Lateral Sclerosis through Interactions with KEAP1

Molecular and Cellular Biology ◽

10.1128/mcb.00087-15 ◽

2015 ◽

Vol 35 (14) ◽

pp. 2385-2399 ◽

Cited By ~ 12

Author(s):

Nadine Bakkar ◽

Arianna Kousari ◽

Tina Kovalik ◽

Yang Li ◽

Robert Bowser

Keyword(s):

Oxidative Stress ◽

Spinal Cord ◽

Amyotrophic Lateral Sclerosis ◽

Motor Neurons ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Antioxidant Response ◽

Cytoplasmic Inclusions ◽

Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the selective loss of motor neurons. Various factors contribute to the disease, including RNA binding protein dysregulation and oxidative stress, but their exact role in pathogenic mechanisms remains unclear. We have recently linked another RNA binding protein, RBM45, to ALS via increased levels of protein in the cerebrospinal fluid of ALS patients and its localization to cytoplasmic inclusions in ALS motor neurons. Here we show RBM45 nuclear exit in ALS spinal cord motor neurons compared to controls, a phenotype recapitulatedin vitroin motor neurons treated with oxidative stressors. We find that RBM45 binds and stabilizes KEAP1, the inhibitor of the antioxidant response transcription factor NRF2. ALS lumbar spinal cord lysates similarly show increased cytoplasmic binding of KEAP1 and RBM45. Binding of RBM45 to KEAP1 impedes the protective antioxidant response, thus contributing to oxidative stress-induced cellular toxicity. Our findings thus describe a novel link between a mislocalized RNA binding protein implicated in ALS (RBM45) and dysregulation of the neuroprotective antioxidant response seen in the disease.

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