Nerve Compression, Nerve Injury, and Nerve Regeneration: An Overview

: Peripheral nerve injuries (PNIs) are accompanied with neuropathic pain and functional disability. Despite improvements in surgical repair techniques in recent years, the functional recovery is yet unsatisfied. Indeed a successful nerve repair depends not only on the surgical strategy but also on the cellular and molecular mechanisms involved in traumatic nerve injury. In contrast to all strategies suggested for nerve repair, pharmacotherapy is a cheap, accessible and non-invasive treatment that can be used immediately after nerve injury. This study aimed to review the effects of some pharmacological agents on the nerve regeneration after traumatic PNI evaluated by functional, histological and electrophysiological assessments. In addition, some cellular and molecular mechanisms responsible for their therapeutic actions, restricted to neural tissue, are suggested. These findings can not only help to find better strategies for peripheral nerve repair, but also to identify the neuropathic effects of various medications and their mechanisms of action.

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Salidroside promotes sciatic nerve regeneration following combined application epimysium conduit and Schwann cells in rats

Experimental Biology and Medicine ◽

10.1177/1535370220906541 ◽

2020 ◽

Vol 245 (6) ◽

pp. 522-531

Author(s):

Jiaqi Li ◽

Yongguang Zhang ◽

Zhimin Yang ◽

Jingxian Zhang ◽

Ren Lin ◽

...

Keyword(s):

Sciatic Nerve ◽

Western Blot ◽

Nerve Regeneration ◽

Schwann Cells ◽

Nerve Injury ◽

Motor Function ◽

Nerve Conduit ◽

Combined Application ◽

Post Operation ◽

Sciatic Nerve Regeneration

Schwann cell and nerve conduit are crucial for nerve regeneration and re-myelination after peripheral nerves injury. To investigate the effects of Salidroside on autogenous epimysium conduit mixed with BD matrigel and RSC96 Schwann cells on an animal model with 5 mm sciatic nerve defect injury in rat, motor function, muscle reinnervation, immunohistochemical staining, retrograded tracing and Western blot were used in this study. The results showed that Salidroside enhanced the compound effects of epimysium conduit mixed with BD matrigel and RSC96 Schwann cells to improve the sciatic functional index and the gastrocnemius muscle weight ratio, which were better than EPM group at 8 weeks and 12 weeks post operation. Immunofluorescence and Western blot results of P75NTR showed that Salidroside improved the sciatic nerve regeneration, and retrograded tracing of CTB-Alexa 488 also supported that Salidroside was better to promote CTB tracer transporting from the distal nerve defect to the ipsilateral dorsal root ganglion and ventral horn of L3-L5 spinal cord on post-operation 8 weeks and 12 weeks. Our results demonstrated that Salidroside improved the effect of autogenous epimysium conduit mixed with BD matrigel and RSC96 Schwann cells on sciatic nerve regeneration in our study. Impact statement Peripheral nerve injury and regeneration remain a major challenge. Although nerve conduit and Schwann cells have been used to study the nerve regeneration, our results demonstrated that Salidroside improved the regenerative effect in a rat model with sciatic nerve injury model, following a combined application of autogenous epimysium conduit mixed with Schwann cells. Different concentrations of Salidroside combining autogenous epimysium conduit and Schwann cells were applied to compare the epimysium conduit group and the epimysium conduit combining Schwann cells group. Based on the results of motor function and muscle reinnervation evaluation, as well as neuronal tracing and expression of P75NTR, our study for the first time suggests that Salidroside may improve the regeneration effect on the sciatic nerve following a combined application of epimysium conduit and RSC96 Schwann cells in rats.

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Dexmedetomidine to Help Nerve Regeneration in a Rat Sciatic Nerve Injury Model

Pain Research and Management ◽

10.1155/2017/9045608 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Wook Jeong ◽

Hsichiang Kung ◽

Chia Chi Cheng ◽

Changwoo Lim ◽

Min Jung Jung ◽

...

Keyword(s):

Sciatic Nerve ◽

Nerve Regeneration ◽

Nerve Injury ◽

Peripheral Nerve Regeneration ◽

Sciatic Nerve Injury ◽

Sprague Dawley ◽

Neuroprotective Effects ◽

Adrenoceptor Agonist ◽

Group 3 ◽

Group 2

Background. Several studies have shown that dexmedetomidine (DXM), a selective α2-adrenoceptor agonist, also has neuroprotective effects. However, its effect on impaired peripheral nerve regeneration has not been studied. Materials and Methods. Forty-five Sprague-Dawley rats were randomly assigned to three groups: group 1 (control SHAM), group 2 (sciatic nerve injury + normal saline), and group 3 (sciatic nerve injury + DXM). The rats of group 3 were subdivided into the following three groups: DXM 0.5, 6, and 20 μg·kg−1 (groups 3A, 3B, and 3C, resp.). The sciatic nerve injury was assessed for nerve regeneration at 2 and 6 weeks. Results. There were no differences between groups 2 and 3 in their sciatic functional index (SFI) values or histological findings at 2 weeks postinjury. However, SFI differences were statistically significant at 6 weeks postinjury in group 3. The gross findings with H&E staining showed that the number of axons was higher in group 3 than in group 2. There was no histological difference according to the DXM concentration. Conclusion. The coincidental functional and histological assessment results of this study suggest that DXM for 6 weeks positively affects damaged peripheral nerves.

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Efect of longitudinally oriented collagen conduit combined with nerve growth factor on nerve regeneration after dog sciatic nerve injury

Journal of Biomedical Materials Research Part B Applied Biomaterials ◽

10.1002/jbm.b.34020 ◽

2017 ◽

Vol 106 (6) ◽

pp. 2131-2139 ◽

Cited By ~ 13

Author(s):

Yao Yao ◽

Yi Cui ◽

Yannan Zhao ◽

Zhifeng Xiao ◽

Xing Li ◽

...

Keyword(s):

Nerve Growth Factor ◽

Growth Factor ◽

Sciatic Nerve ◽

Nerve Regeneration ◽

Nerve Injury ◽

Sciatic Nerve Injury ◽

Nerve Growth

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The effect of lithium and lithium-loaded hyaluronic acid hydrogel applications on nerve regeneration and recovery of motor functions in peripheral nerve injury

RENDICONTI LINCEI ◽

10.1007/s12210-020-00919-5 ◽

2020 ◽

Vol 31 (3) ◽

pp. 889-904

Author(s):

Atacan Emre Kocman ◽

Ilknur Dag ◽

Tayfun Sengel ◽

Erdem Soztutar ◽

Mediha Canbek

Keyword(s):

Hyaluronic Acid ◽

Peripheral Nerve ◽

Nerve Regeneration ◽

Nerve Injury ◽

Peripheral Nerve Injury ◽

Motor Functions ◽

Hyaluronic Acid Hydrogel

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The Regenerative Potential of Facial Nerve Motoneurons following Chronic Axotomy in Rats

Neural Plasticity ◽

10.1155/2020/8884511 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Yusu Ni ◽

Diyan Chen ◽

Yi Jiang ◽

Danhong Qiu ◽

Wen Li ◽

...

Keyword(s):

Facial Nerve ◽

Nerve Regeneration ◽

Nerve Injury ◽

Sonic Hedgehog ◽

Neuronal Marker ◽

Facial Nerve Injury ◽

Transmission Electron ◽

Male Wistar Rats ◽

Mrna And Protein Expression ◽

Time Point

Background. The precise mechanisms of nerve regeneration remain unclear. The potential of facial nerve regeneration and probable mechanisms involved following chronic facial nerve injury should be further studied. Methods. Adult male Wistar rats were used to model either (i) facial nerve injury (axotomy) or (ii) reinjury (chronic axotomy followed by a second axotomy within 5 months). The rats were housed in the animal facility of the Eye and ENT Hospital of Shanghai Medical School, Fudan University (Shanghai, China). Expression of Shh (sonic hedgehog) and growth-associated protein 43 (GAP43, a neuronal marker) was detected in bilateral facial nuclei using reverse transcriptase PCR, western blotting analysis, and immunohistochemistry. The number of surviving motoneurons was quantified, and facial nerve regeneration was examined using transmission electron microscopy. Results. Reinjury of the facial nerve 12 weeks after the first axotomy resulted in upregulation of GAP43 mRNA and protein expression in neurons ipsilateral to the axotomy; immunohistochemistry revealed that Shh expression was higher compared with control side facial nuclei at the same time point. GAP43 expression subsequently decreased. Conclusion. The greatest regeneration potential of the facial nerve occurred within 5 months following chronic axotomy in rats, and regeneration may involve the Shh signaling pathway.

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