Reorganization of Somatosensory Cortex After Nerve and Spinal Cord Injury

Physiology ◽  
1998 ◽  
Vol 13 (3) ◽  
pp. 143-149 ◽  
Author(s):  
Neeraj Jain ◽  
Sherre L. Florence ◽  
Jon H. Kaas
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Peripheral Nerve ◽  
Somatosensory Cortex ◽  
Tonic Inhibition ◽  
Synaptic Efficacy ◽  
Spinal Lesions ◽  
Mature Brain ◽  
Cord Injury ◽  
Neuronal Sprouting

Somatotopic maps in the mature brain reorganize in response to deafferentation by peripheral nerve cut, amputations, or spinal lesions. Mechanisms underlying these changes may range from altered tonic inhibition and synaptic efficacy to neuronal sprouting. An understanding of these mechanisms could guide interventions that potentiate recovery from such injuries.

Transplantation Strategies for Spinal Cord Injury Based on Microenvironment Modulation

2020 ◽  
Vol 15 (6) ◽  
pp. 522-530
Author(s):  
Jiawei Shu ◽  
Feng Cheng ◽  
Zhe Gong ◽  
Liwei Ying ◽  
Chenggui Wang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Peripheral Nerve ◽  
Nerve Injury ◽  
Autonomic Dysfunction ◽  
Peripheral Nerve Injury ◽  
Therapeutic Effects ◽  
Permanent Damage ◽  
Cord Injury ◽  
Severe Motor

Spinal cord injury (SCI) is different from peripheral nerve injury; it results in devastating and permanent damage to the spine, leading to severe motor, sensory and autonomic dysfunction. SCI produces a complex microenvironment that can result in hemorrhage, inflammation and scar formation. Not only does it significantly limit regeneration, but it also challenges a multitude of transplantation strategies. In order to promote regeneration, researchers have recently begun to focus their attention on strategies that manipulate the complicated microenvironment produced by SCI. And some have achieved great therapeutic effects. Hence, reconstructing an appropriate microenvironment after transplantation could be a potential therapeutic solution for SCI. In this review, first, we aim to summarize the influential compositions of the microenvironment and their different effects on regeneration. Second, we highlight recent research that used various transplantation strategies to modulate different microenvironments produced by SCI in order to improve regeneration. Finally, we discuss future transplantation strategies regarding SCI.

scholarly journals Descending propriospinal neurons mediate restoration of locomotor function following spinal cord injury

2017 ◽  
Vol 117 (1) ◽  
pp. 215-229 ◽  
Author(s):  
Katelyn N. Benthall ◽  
Ryan A. Hough ◽  
Andrew D. McClellan
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Axonal Regeneration ◽  
Central Pattern Generators ◽  
Burst Activity ◽  
Compensatory Mechanism ◽  
Spinal Lesions ◽  
Cord Injury ◽  
Recovery Times ◽  
Indirect Activation

Following spinal cord injury (SCI) in the lamprey, there is virtually complete recovery of locomotion within a few weeks, but interestingly, axonal regeneration of reticulospinal (RS) neurons is mostly limited to short distances caudal to the injury site. To explain this situation, we hypothesize that descending propriospinal (PS) neurons relay descending drive from RS neurons to indirectly activate spinal central pattern generators (CPGs). In the present study, the contributions of PS neurons to locomotor recovery were tested in the lamprey following SCI. First, long RS neuron projections were interrupted by staggered spinal hemitransections on the right side at 10% body length (BL; normalized from the tip of the oral hood) and on the left side at 30% BL. For acute recovery conditions (≤1 wk) and before axonal regeneration, swimming muscle burst activity was relatively normal, but with some deficits in coordination. Second, lampreys received two spaced complete spinal transections, one at 10% BL and one at 30% BL, to interrupt long-axon RS neuron projections. At short recovery times (3–5 wk), RS and PS neurons will have regenerated their axons for short distances and potentially established a polysynaptic descending command pathway. At these short recovery times, swimming muscle burst activity had only minor coordination deficits. A computer model that incorporated either of the two spinal lesions could mimic many aspects of the experimental data. In conclusion, descending PS neurons are a viable mechanism for indirect activation of spinal locomotor CPGs, although there can be coordination deficits of locomotor activity. NEW & NOTEWORTHY In the lamprey following spinal lesion-mediated interruption of long axonal projections of reticulospinal (RS) neurons, sensory stimulation still elicited relatively normal locomotor muscle burst activity, but with some coordination deficits. Computer models incorporating the spinal lesions could mimic many aspects of the experimental results. Thus, after disruption of long-axon projections from RS neurons in the lamprey, descending propriospinal (PS) neurons appear to be a viable compensatory mechanism for indirect activation of spinal locomotor networks.

scholarly journals Percutaneous peripheral nerve stimulation for treatment of shoulder pain after spinal cord injury: A case report

2017 ◽  
Vol 41 (1) ◽  
pp. 119-124 ◽  
Author(s):  
Daniela Mehech ◽  
Melvin Mejia ◽  
Gregory A. Nemunaitis ◽  
John Chae ◽  
Richard D. Wilson
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Case Report ◽  
Peripheral Nerve ◽  
Shoulder Pain ◽  
Nerve Stimulation ◽  
Peripheral Nerve Stimulation ◽  
Cord Injury

scholarly journals The human ApoE4 variant reduces functional recovery and neuronal sprouting after incomplete spinal cord injury in male mice

2020 ◽  
Author(s):  
Carlos A. Toro ◽  
Jens Hansen ◽  
Mustafa M. Siddiq ◽  
Kaitlin Johnson ◽  
Wei Zhao ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Inflammatory Responses ◽  
Synaptic Activity ◽  
Cord Injury ◽  
Hospital Stays ◽  
Human Apoe3 ◽  
Neuronal Sprouting ◽  
Apoe Genotypes ◽  
Upregulated Genes

AbstractSpinal cord injury (SCI) is a devastating form of neurotrauma. Patients who carry one or two ApoE4 alleles show worse functional outcomes and longer hospital stays after SCI but the cellular and molecular underpinnings for this genetic link remain poorly understood. Thus, there is a great need to generate animal models to accurately replicate the genetic determinants of outcomes after SCI to spur development of treatments that improve physical function. Here, we examined outcomes after a moderate contusion SCI of transgenic mice expressing human ApoE3 or ApoE4. ApoE4 mice have worse locomotor function and coordination after SCI. Histological examination revealed greater glial staining in ApoE4 mice after SCI associated with reduced levels of neuronal sprouting markers. Bulk RNA sequencing revealed that subcellular processes (SCPs), such as extracellular matrix organization and inflammatory responses, were highly-ranked among upregulated genes at 7 days after SCI in ApoE4 variants. Conversely, SCPs related to neuronal action potential and neuron projection development were increased in ApoE3 mice at 21 days. In summary, our results reveal a clinically relevant SCI mouse model that recapitulates the influence of ApoE genotypes on post-SCI function in individuals who carry these alleles and suggest that the mechanisms underlying worse recovery for ApoE4 animals involve glial activation and loss of sprouting and synaptic activity.

scholarly journals EA Improves the Motor Function in Rats with Spinal Cord Injury by Inhibiting Signal Transduction of Semaphorin3A and Upregulating of the Peripheral Nerve Networks

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Rong Hu ◽  
Haipeng Xu ◽  
Yaheng Jiang ◽  
Yi Chen ◽  
Kelin He ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Peripheral Nerve ◽  
Motor Function ◽  
Gray Matter ◽  
Ventral Horn ◽  
Damage Site ◽  
Central Tube ◽  
Spinal Cord Segment ◽  
Cord Injury

Peripheral nerve networks (PNNs) play a vital role in the neural recovery after spinal cord injury (SCI). Electroacupuncture (EA), as an alternative medicine, has been widely used in SCI and was proven to be effective on neural functional recovery. In this study, the interaction between PNNs and semaphrin3A (Sema3A) in the recovery of the motor function after SCI was observed, and the effect of EA on them was evaluated. After the establishment of the SCI animal model, we found that motor neurons in the ventral horn of the injured spinal cord segment decreased, Nissl bodies were blurry, and PNNs and Sema3A as well as its receptor neuropilin1 (NRP1) aggregated around the central tube of the gray matter of the spinal cord. When we knocked down the expression of Sema3A at the damage site, NRP1 also downregulated, importantly, PNNs concentration decreased, and tenascin-R (TN-R) and aggrecan were also reduced, while the Basso-Beattie-Bresnahan (BBB) motor function score dramatically increased. In addition, when conducting EA stimulation on Jiaji (EX-B2) acupoints, the highly upregulated Sema3A and NRP1 were reversed post-SCI, which can lessen the accumulation of PNNs around the central tube of the spinal cord gray matter, and simultaneously promote the recovery of motor function in rats. These results suggest that EA may further affect the plasticity of PNNs by regulating the Sema3A signal and promoting the recovery of the motor function post-SCI.

Peripheral nerve grafts promoting central nervous system regeneration after spinal cord injury in the primate

2002 ◽  
Vol 96 (2) ◽  
pp. 197-205 ◽  
Author(s):  
Allan D. O. Levi ◽  
Hector Dancausse ◽  
Xiuming Li ◽  
Suzanne Duncan ◽  
Laura Horkey ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Spinal Cord Injury ◽  
Nervous System ◽  
Peripheral Nerve ◽  
Content Type ◽  
Nerve Grafts ◽  
Cord Injury ◽  
Peripheral Nerve Grafts ◽  
Fine Print

Object. Partial restoration of hindlimb function in adult rats following spinal cord injury (SCI) has been demonstrated using a variety of transplantation techniques. The purpose of the present study was twofold: 1) to determine whether strategies designed to promote regeneration in the rat can yield similar results in the primate; and 2) to establish whether central nervous system (CNS) regeneration will influence voluntary grasping and locomotor function in the nonhuman primate. Methods. Ten cynomologus monkeys underwent T-11 laminectomy and resection of a 1-cm length of hemispinal cord. Five monkeys received six intercostal nerve autografts and fibrin glue containing acidic fibroblast growth factor (2.1 µg/ml) whereas controls underwent the identical laminectomy procedure but did not receive the nerve grafts. At 4 months postgrafting, the spinal cord—graft site was sectioned and immunostained for peripheral myelin proteins, biotinylated dextran amine, and tyrosine hydroxylase, whereas the midpoint of the graft was analyzed histologically for the total number of myelinated axons within and around the grafts. The animals underwent pre- and postoperative testing for changes in voluntary hindlimb grasping and gait. Conclusions. 1) A reproducible model of SCI in the primate was developed. 2) Spontaneous recovery of the ipsilateral hindlimb function occurred in both graft- and nongraft—treated monkeys over time without evidence of recovering the ability for voluntary tasks. 3) Regeneration of the CNS from proximal spinal axons into the peripheral nerve grafts was observed; however, the grafts did not promote regeneration beyond the lesion site. 4) The grafts significantly enhanced (p < 0.0001) the regeneration of myelinated axons into the region of the hemisected spinal cord compared with the nongrafted animals.

scholarly journals Exercise and Peripheral Nerve Grafts as a Strategy To Promote Regeneration after Acute or Chronic Spinal Cord Injury

2017 ◽  
Vol 34 (10) ◽  
pp. 1909-1914 ◽  
Author(s):  
Catherine C. Theisen ◽  
Rahul Sachdeva ◽  
Scarlett Austin ◽  
Danielle Kulich ◽  
Victoria Kranz ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Peripheral Nerve ◽  
Chronic Spinal Cord Injury ◽  
Nerve Grafts ◽  
Cord Injury ◽  
Peripheral Nerve Grafts
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