Project description:To investigate the mechanism of electrical stimulation in the repair of spinal cord injury, we established a rat model of spinal cord injury. Then, we used RNA-SEQ data obtained from ES treatment and 6 different rat models of spinal cord injury for gene expression profile analysis.
Project description:Electrical stimulation can augment or modify neuronal function and can have therapeutic benefits for certain neurological disorders. There is evidence that enhancing spinal excitability with either epidural or transcutaneous stimulation can restore some volitional motor output after spinal cord injury (SCI). Lumbosacral epidural stimulation temporarily improves locomotor and autonomic function in both rodents and humans with SCI. When combined with overground locomotor training enabled by a weight-supporting device, epidural electrical stimulation (EES) promotes extensive reorganization of residual neural pathways that improves locomotion after stopping stimulation. However, the exact mechanism underlying the reconstruction of spinal cord neural circuits with electrical stimulation is not yet known. Thus, we developed a epidural electrical and muscle stimulation(EEMS) system at the interface of the spinal cord and muscle to mimic feedforward and feedback electrical signals in spinal sensorimotor circuits. Using methods of motor function evaluation, neural circuit tracing and neural signal recording, we discovered a unique stimulus frequency of 10-20 Hz under EEMS conditions that was required for structural and functional reconstruction of spinal sensorimotor circuits. Single-cell transcriptome analysis of EEMS activated motoneurons characterized molecular networks involved in spinal sensorimotor circuit reconstruction. This study provides insights into neural signal decoding during spinal sensorimotor circuit reconstruction, and indicates a technological approach for the clinical treatment of SCI.
Project description:Spinal cord injury disrupts ascending and descending neural signals causing sensory and motor dysfunction below the injury. Neuromodulation with electrical stimulation is used in both clinical and research settings to induce neural plasticity and improve functional recovery following injury. However, the mechanisms by which electrical stimulation affects recovery remain unclear. In this study we examined the effects of cortical electrical stimulation following injury on transcription at several levels of the central nervous system. We performed a unilateral cervical spinal contusion injury in rats and delivered stimulation for one week to the contralesional motor cortex to activate a descending motor tract.RNA was purified from bilateral subcortical white matter, and 3 levels of the spinal cord. Here we provide the complete data set in the hope that it will be useful for researchers studying electrical stimulation as a therapy to improve recovery from the deficits associated with spinal cord injury.
Project description:Purpose: The goal of this study was to determine the gene expression changes that occur over 7 days in parralyzed muscle in response to isometric contraction elicited by electrical stimulation initiated 4 months after spinal cord injury and to compare such changes to those observed in a normal muscle subjected to overload. Methods: Electrical stimulation of the soleus and plantaris muscle was stimulated in female rats with complete transection of the spinal cord at the interspace between the 9th and 10th thoracic vertebrae. Stimulation was begun 16 weeks after spinal cord transection and produced near-isometric contraction of soleus, plantaris and tibialis anterior. Muscle was analyzed at 1, 2 and 7 days after starting exercise with electrical stimulation. To provide a baseline reference for gene expression at 16 weeks after spinal cord injury, muscle was also analysed from an additional group of spinal cord transected animals. One additional group of animals with a sham-spinal cord injury was included to provide information about gene expression in neurologically intact animals of similar age. In parallel studies, rats underwent bilateral gastrocnemius ablation to overload soleus and plantaris, or a sham ablation as a control. Muscle was analyzed at 1, 3 and 7 days after gastrocnemius ablation or sham-ablation. Gene expression was determined using Affymetrix Rat Exon microarrays. For each group of animals, microarray analysis was performed for soleus muscle for each of 3 separate animals, using one array per animal. Control sammples for the spinal cord injured groups included a group of animals with a Sham-spinal cord injury, and a group of spinal cord injured animals that did not get electrical stimulation. The comparator for determining fold-change expression values was the spinal cord injured group that did not receive electrical stimulation. For each day after gastrocnemius ablation, a control was included that received all procedures needed for this ablation except cutting the distal insertion of the gastrocnemius into the Achilles tendon to control for effects of the surgery on gene expression.
Project description:The goal of this study is to elucidate the influence of hemisection injury at thoracic spinal cord (T9) and epidural electrical spinal stimulation (L2-S1) on transcriptome of injured thoracic spinal cord. mRNA profiles of spinal cord at 5 days-post injury with or without epidural electrical spinal stimulation (L2-S1) and before injury were generated. Our study represents the detailed analysis of transcriptomes of injured spinal cord with biologic replicates, generated by RNA-seq technology.
Project description:The characteristics of electrical signals-mediated neural circuits reconstruction remain poorly understood. We initially developed a spinal-muscle synergistic bidirectional electrical stimulation (SBES) protocol to mimic feedforward and feedback electrical signals in spinal sensorimotor circuits. The results indicate that sensorimotor circuits could be precisely reassembled in structure and function levels by 10-20 Hz SBES. To gain mechanistic insights into the reassembly of the spinal sensorimotor circuits with 10-20 Hz SBES, we performed gene expression profiling analysis in motoneurons. Gene ontology (GO) analysis showed that one group of GO terms accounted for a large fraction of the upregulated transcripts. This group includes axon growth-related cellular functions, such as cell adhesion, regulation of cell growth, and cell projection assembly. Statistical analysis of the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways revealed sixteen signaling pathways were involved, two of which were related to the regulation of axonal regeneration (PI3K-Akt signaling pathway and cAMP signaling pathway). This study provides insights into neural signal decoding during spinal sensorimotor circuit reconstruction.
Project description:Smart-seq2 of spinal cord motor neurons reveals transcriptomic changes in mice with spinal cord injury after synergistic bidirectional electrical stimulation of specific frequencies
Project description:The spinal cord after injury shows altered transcription in numerous genes. We tested in a pilot study whether the nucleus raphé magnus, a descending serotonergic brainstem region whose stimulation improves recovery after incomplete spinal cord injury, can influence these transcriptional changes. Rats received 2 hours of low-frequency electrical stimulation in the raphé magnus three days after an impact contusion at segment T8. Comparison groups lacked injuries or activated stimulators or both. Immediately following stimulation, spinal cords were extracted, their RNA transcriptome sequenced, and differential gene expression quantified. Confirming many previous studies, injury primarily increased inflammatory and immune transcripts and decreased those related to lipid and cholesterol synthesis and neuronal signaling. Stimulation plus injury, contrasted with injury alone, caused significant changes in 43 transcripts (39 increases, 4 decreases), all protein-coding. Injury itself decreased only four of these 43 transcripts, all reversed by stimulation, and increased none of them. The non-specific 5-HT7 receptor antagonist pimozide reversed 25 of the 43 changes. Stimulation in intact rats principally caused decreases in transcripts related to oxidative phosphorylation, none of which were altered by stimulation in injury. Gene ontology (biological process) annotations comparing stimulation with either no stimulation or pimozide treatment in injured rats highlighted defense responses to lipopolysaccharides and microorganisms, and also erythrocyte development and oxygen transport (possibly yielding cellular oxidant detoxification). Connectivity maps of human orthologous genes generated in the CLUE database of perturbagen-response transcriptional signatures showed that drug classes whose effects in injured rats most closely resembled stimulation without pimozide include peroxisome proliferator-activated receptor agonists and angiotensin receptor blockers, which are reportedly beneficial in spinal cord injury. Thus, the initial transcriptional response of injured spinal cord to raphé magnus stimulation is upregulation of genes that in various ways are mostly protective, some probably located in recently arrived myeloid cells.