Glial scar and neuroregeneration: histological, functional, and magnetic resonance imaging analysis in chronic spinal cord injury

2010 ◽  
Vol 13 (2) ◽  
pp. 169-180 ◽  
Author(s):  
Rong Hu ◽  
Jianjun Zhou ◽  
Chunxia Luo ◽  
Jiangkai Lin ◽  
Xianrong Wang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Mr Imaging ◽  
Rating Scale ◽  
Time Window ◽  
Critical Time ◽  
Glial Scar ◽  
Electrophysiological Recording ◽  
Axonal Regrowth ◽  
Cord Injury

Object A glial scar is thought to be responsible for halting neuroregeneration following spinal cord injury (SCI). However, little quantitative evidence has been provided to show the relationship of a glial scar and axonal regrowth after injury. Methods In this study performed in rats and dogs, a traumatic SCI model was made using a weight-drop injury device, and tissue sections were stained with H & E for immunohistochemical analysis. The function and behavior of model animals were tested using electrophysiological recording and the Basso-Beattie-Bresnahan Locomotor Rating Scale, respectively. The cavity in the spinal cord after SCI in dogs was observed using MR imaging. Results The morphological results showed that the formation of an astroglial scar was defined at 4 weeks after SCI. While regenerative axons reached the vicinity of the lesion site, the glial scar blocked the extension of regrown axons. In agreement with these findings, the electrophysiological, behavioral, and in vivo MR imaging tests showed that functional recovery reached a plateau at 4 weeks after SCI. The thickness of the glial scars in the injured rat spinal cords was also measured. The mean thickness of the glial scar rostral and caudal to the lesion cavity was 107.00 ± 20.12 μm; laterally it was 69.92 ± 15.12 μm. Conclusions These results provide comprehensive evidence indicating that the formation of a glial scar inhibits axonal regeneration at 4 weeks after SCI. This study reveals a critical time window of postinjury recovery and a detailed spatial orientation of glial scar, which would provide an important basis for the development of therapeutic strategy for glial scar ablation.

scholarly journals The Biology of Regeneration Failure and Success After Spinal Cord Injury

2018 ◽  
Vol 98 (2) ◽  
pp. 881-917 ◽  
Author(s):  
Amanda Phuong Tran ◽  
Philippa Mary Warren ◽  
Jerry Silver
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Functional Recovery ◽  
Axonal Regeneration ◽  
Molecular Mechanisms ◽  
Glial Scar ◽  
Perineuronal Net ◽  
Physical Trauma ◽  
Axonal Regrowth ◽  
Cord Injury

Since no approved therapies to restore mobility and sensation following spinal cord injury (SCI) currently exist, a better understanding of the cellular and molecular mechanisms following SCI that compromise regeneration or neuroplasticity is needed to develop new strategies to promote axonal regrowth and restore function. Physical trauma to the spinal cord results in vascular disruption that, in turn, causes blood-spinal cord barrier rupture leading to hemorrhage and ischemia, followed by rampant local cell death. As subsequent edema and inflammation occur, neuronal and glial necrosis and apoptosis spread well beyond the initial site of impact, ultimately resolving into a cavity surrounded by glial/fibrotic scarring. The glial scar, which stabilizes the spread of secondary injury, also acts as a chronic, physical, and chemo-entrapping barrier that prevents axonal regeneration. Understanding the formative events in glial scarring helps guide strategies towards the development of potential therapies to enhance axon regeneration and functional recovery at both acute and chronic stages following SCI. This review will also discuss the perineuronal net and how chondroitin sulfate proteoglycans (CSPGs) deposited in both the glial scar and net impede axonal outgrowth at the level of the growth cone. We will end the review with a summary of current CSPG-targeting strategies that help to foster axonal regeneration, neuroplasticity/sprouting, and functional recovery following SCI.

scholarly journals Genes and miRNAs as Hurdles and Promoters of Corticospinal Tract Regeneration in Spinal Cord Injury

2021 ◽  
Vol 9 ◽  
Author(s):  
Marina Boido ◽  
Alessandro Vercelli
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Axonal Regeneration ◽  
Chronic Phase ◽  
Axon Growth ◽  
Glial Scar ◽  
Neural Regeneration ◽  
Axonal Regrowth ◽  
Cord Injury ◽  
Sensory Motor

Spinal cord injury (SCI) is a devastating lesion to the spinal cord, which determines the interruption of ascending/descending axonal tracts, the loss of supraspinal control of sensory-motor functions below the injured site, and severe autonomic dysfunctions, dramatically impacting the quality of life of the patients. After the acute inflammatory phase, the progressive formation of the astrocytic glial scar characterizes the acute-chronic phase: such scar represents one of the main obstacles to the axonal regeneration that, as known, is very limited in the central nervous system (CNS). Unfortunately, a cure for SCI is still lacking: the current clinical approaches are mainly based on early vertebral column stabilization, anti-inflammatory drug administration, and rehabilitation programs. However, new experimental therapeutic strategies are under investigation, one of which is to stimulate axonal regrowth and bypass the glial scar. One major issue in axonal regrowth consists of the different genetic programs, which characterize axonal development and maturation. Here, we will review the main hurdles that in adulthood limit axonal regeneration after SCI, describing the key genes, transcription factors, and miRNAs involved in these processes (seen their reciprocal influencing action), with particular attention to corticospinal motor neurons located in the sensory-motor cortex and subjected to axotomy in case of SCI. We will highlight the functional complexity of the neural regeneration programs. We will also discuss if specific axon growth programs, that undergo a physiological downregulation during CNS development, could be reactivated after a spinal cord trauma to sustain regrowth, representing a new potential therapeutic approach.

scholarly journals A Collagen-Based Scaffold for Promoting Neural Plasticity in a Rat Model of Spinal Cord Injury

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2245
Author(s):  
Jue-Zong Yeh ◽  
Ding-Han Wang ◽  
Juin-Hong Cherng ◽  
Yi-Wen Wang ◽  
Gang-Yi Fan ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Rat Model ◽  
Neural Plasticity ◽  
Collagen Scaffold ◽  
Glial Scar ◽  
Beneficial Effects ◽  
Cord Injury

In spinal cord injury (SCI) therapy, glial scarring formed by activated astrocytes is a primary problem that needs to be solved to enhance axonal regeneration. In this study, we developed and used a collagen scaffold for glial scar replacement to create an appropriate environment in an SCI rat model and determined whether neural plasticity can be manipulated using this approach. We used four experimental groups, as follows: SCI-collagen scaffold, SCI control, normal spinal cord-collagen scaffold, and normal control. The collagen scaffold showed excellent in vitro and in vivo biocompatibility. Immunofluorescence staining revealed increased expression of neurofilament and fibronectin and reduced expression of glial fibrillary acidic protein and anti-chondroitin sulfate in the collagen scaffold-treated SCI rats at 1 and 4 weeks post-implantation compared with that in untreated SCI control. This indicates that the collagen scaffold implantation promoted neuronal survival and axonal growth within the injured site and prevented glial scar formation by controlling astrocyte production for their normal functioning. Our study highlights the feasibility of using the collagen scaffold in SCI repair. The collagen scaffold was found to exert beneficial effects on neuronal activity and may help in manipulating synaptic plasticity, implying its great potential for clinical application in SCI.

Review of clinical trials of neuroprotection in acute spinal cord injury

1999 ◽  
Vol 6 (1) ◽  
pp. E10 ◽  
Author(s):  
Charles H. Tator ◽  
Michael G. Fehlings
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Clinical Trials ◽  
Treatment Time ◽  
Time Window ◽  
Current Knowledge ◽  
Acute Spinal Cord Injury ◽  
Randomized Controlled Studies ◽  
Cord Injury ◽  
Therapeutic Time Window

In this paper the authors review the clinical trials of neuroprotection that have been performed for the treatment of acute spinal cord injury (SCI). The biological rationale for the selection of each treatment modality is discussed with reference to current knowledge of the principles in the management of acute SCI as well as the primary and secondary injury mechanisms identified by experimental and clinical studies of the pathophysiology of acute SCI. The trials are evaluated with regard to the availability and use of accurate clinical outcome measures, and the methodologies of the trials are critically evaluated with an emphasis on prospective randomized controlled studies. A detailed description and critical analysis are provided of the results of the 10 clinical trials conducted to date in which a randomized prospective controlled design has been used. The issue of the therapeutic time window in acute SCI is discussed. To date, methylprednisolone is the only effective neuroprotective agent that has been established for use in human SCI, and the only therapeutic time window established in human SCI is a maximum trauma-to-treatment time of 8 hours.

MR Imaging for Assessing Injury Severity and Prognosis in Acute Traumatic Spinal Cord Injury

2019 ◽  
Vol 57 (2) ◽  
pp. 319-339 ◽  
Author(s):  
Jason F. Talbott ◽  
John Russell Huie ◽  
Adam R. Ferguson ◽  
Jacqueline C. Bresnahan ◽  
Michael S. Beattie ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Mr Imaging ◽  
Injury Severity ◽  
Traumatic Spinal Cord Injury ◽  
Cord Injury

Support of axonal regrowth by endogenous mechanisms following spinal cord injury in adult rats

2001 ◽  
Vol 21 (3) ◽  
pp. 188-202 ◽  
Author(s):  
Norman R West ◽  
Victoria LeBlanc ◽  
George H Collins
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Adult Rats ◽  
Axonal Regrowth ◽  
Cord Injury
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