Journal of neurotrauma
-
Journal of neurotrauma · Aug 2018
Differential Adaptations of the Musculoskeletal System after Spinal Cord Contusion and Transection in Rats.
Spinal cord injury (SCI) causes impaired neuronal function with associated deficits in the musculoskeletal system, which can lead to permanent disability. Here, the impact of SCI on in vivo musculoskeletal adaptation was determined by studying deficits in locomotor function and analyzing changes that occur in the muscle and bone compartments within the rat hindlimb after contusion or transection SCI. Analyses of locomotor patterns, as assessed via the Basso, Beattie, and Bresnahan (BBB) rating scale, revealed that transection animals showed significant deficits, while the contusion group had moderate deficits, compared with naïve groups. ⋯ In general, values of bone volume per total bone volume (BV/TV) were similar across the SCI groups. Significant decreases were observed, however, in the transection animals for bone mineral content, bone mineral density, and three-dimensional trabecular structure parameters (trabecular number, thickness, and spacing) compared with the naïve and contusion groups. Together, these findings suggest an altered musculoskeletal system can be correlated directly to motor dysfunctions seen after SCI.
-
Journal of neurotrauma · Aug 2018
Effects of Mitochondrial Transplantation on Bioenergetics, Cellular Incorporation, and Functional Recovery after Spinal Cord Injury.
Our previous studies reported that pharmacological maintenance of mitochondrial bioenergetics after experimental spinal cord injury (SCI) provided functional neuroprotection. Recent evidence indicates that endogenous mitochondrial transfer is neuroprotective as well, and, therefore, we extended these studies with a novel approach to transplanting exogenous mitochondria into the injured rat spinal cord. Using a rat model of L1/L2 contusion SCI, we herein report that transplantation of exogenous mitochondria derived from either cell culture or syngeneic leg muscle maintained acute bioenergetics of the injured spinal cord in a concentration-dependent manner. ⋯ Despite their contribution to the maintenance of normal bioenergetics, mitochondrial transplantation did not yield long-term functional neuroprotection as assessed by overall tissue sparing or recovery of motor and sensory functions. These experiments are the first to investigate mitochondrial transplantation as a therapeutic approach to treating spinal cord injury. Our initial bioenergetic results are encouraging, and although they did not translate into improved long-term outcome measures, caveats and technical hurdles are discussed that can be addressed in future studies to potentially increase long-term efficacy of transplantation strategies.
-
Journal of neurotrauma · Aug 2018
Early Predictors of Global Functional Outcome after Traumatic Spinal Cord Injury: A Systematic Review.
Accurately predicting functional recovery is an asset for all clinicians and decision makers involved in the care of patients with acute traumatic spinal cord injury (TSCI). Unfortunately, there is a lack of information on the relative importance of significant predictors of global functional outcome. There is also a need for identifying functional predictors that can be timely optimized by the medical and rehabilitation teams throughout the hospitalizations phases. ⋯ Based on the compiled data, this review proposes a rating of early factors associated to global functional outcome according to their importance and their potential to be modified by the medical/rehabilitation team throughout the early phases of hospitalization. It also proposes a new conceptual framework that illustrates the impact of specific categories of factors and their interaction with each other. Ultimately, this review aims to guide clinicians and researchers in improving the continuum of care throughout early phases post-SCI.
-
Journal of neurotrauma · Aug 2018
Grafts of Olfactory Stem Cells Restore Breathing and Motor Functions after Rat Spinal Cord Injury.
The transplantation of olfactory ecto-mesenchymal stem cells (OEMSCs) could be a helpful therapeutic strategy for spinal cord repair. Using an acute rat model of high cervical contusion that provokes a persistent hemidiaphragmatic and foreleg paralysis, we evaluated the therapeutic effect of a delayed syngeneic transplantation (two days post-contusion) of OEMSCs within the injured spinal cord. Respiratory function was assessed using diaphragmatic electromyography and neuroelectrophysiological recordings of phrenic nerves (innervating the diaphragm). ⋯ Some grafted stem cells adopted a neuronal phenotype, and axonal sparing was observed in the injury site. The therapeutic effect on the supraspinal command is presumably because of both neuronal replacements and beneficial paracrine effects on the injury area. Our study provides evidence that nasal OEMSCs could be a first step in clinical application, particularly in patients with reduced breathing/locomotor movements.
-
Journal of neurotrauma · Aug 2018
The Role of Ventral Tegmental Area Gamma-Aminobutyric Acid in Chronic Neuropathic Pain after Spinal Cord Injury in Rats.
Spinal cord injury (SCI) frequently results in chronic neuropathic pain (CNP). However, the understanding of brain neural circuits in CNP modulation is unclear. The present study examined the changes of ventral tegmental area (VTA) putative GABAergic and dopaminergic neuronal activity with CNP attenuation in rats. ⋯ With regard to in vivo electrophysiology, VTA putative GABAergic neuronal activity (13.6 ± 1.7 spikes/sec) and putative dopaminergic neuronal activity (2.4 ± 0.8 spikes/sec) were increased and decreased, respectively, in the SCI group compared to the sham control group. These neuronal activities were reversed by i.v. administration of morphine. The present study suggests that chronic increase of GABAergic neuronal activity suppresses dopaminergic neuronal activity in the VTA and is responsible for negative emotion and motivation for attenuation of SCI-induced CNP.