scholarly journals Reduced Renshaw Recurrent Inhibition after Neonatal Sciatic Nerve Crush in Rats

2014 ◽  
Vol 2014 ◽  
pp. 1-11
Author(s):  
Liang Shu ◽  
Jingjing Su ◽  
Lingyan Jing ◽  
Ying Huang ◽  
Yu Di ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Recurrent Inhibition ◽  
Crush Injury ◽  
Sciatic Nerve Crush ◽  
Nerve Crush ◽  
Nerve Crush Injury

Renshaw recurrent inhibition (RI) plays an important gated role in spinal motion circuit. Peripheral nerve injury is a common disease in clinic. Our current research was designed to investigate the change of the recurrent inhibitory function in the spinal cord after the peripheral nerve crush injury in neonatal rat. Sciatic nerve crush was performed on 5-day-old rat puppies and the recurrent inhibition between lateral gastrocnemius-soleus (LG-S) and medial gastrocnemius (MG) motor pools was assessed by conditioning monosynaptic reflexes (MSR) elicited from the sectioned dorsal roots and recorded either from the LG-S and MG nerves by antidromic stimulation of the synergist muscle nerve. Our results demonstrated that the MSR recorded from both LG-S or MG nerves had larger amplitude and longer latency after neonatal sciatic nerve crush. The RI in both LG-S and MG motoneuron pools was significantly reduced to virtual loss (15–20% of the normal RI size) even after a long recovery period upto 30 weeks after nerve crush. Further, the degree of the RI reduction after tibial nerve crush was much less than that after sciatic nerve crush indicatig that the neuron-muscle disconnection time is vital to the recovery of the spinal neuronal circuit function during reinnervation. In addition, sciatic nerve crush injury did not cause any spinal motor neuron loss but severally damaged peripheral muscle structure and function. In conclusion, our results suggest that peripheral nerve injury during neonatal early development period would cause a more sever spinal cord inhibitory circuit damage, particularly to the Renshaw recurrent inhibition pathway, which might be the target of neuroregeneration therapy.

scholarly journals Lack of correlation between spinal microgliosis and long-term development of tactile hypersensitivity in two different sciatic nerve crush injury

2021 ◽  
Vol 17 ◽  
pp. 174480692110113
Author(s):  
Hyoung Woo Kim ◽  
Chan Hee Won ◽  
Seog Bae Oh
Keyword(s):  
Spinal Cord ◽  
Chronic Pain ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Sensory Function ◽  
Crush Injury ◽  
Sciatic Nerve Crush

Microglia activation following peripheral nerve injury has been shown to contribute to central sensitization of the spinal cord for the development of neuropathic pain. In a recent study, we reported that the amount of nerve damage does not necessarily correlate with chronic pain development. Here we compared the response of spinal microglia, using immunohistochemistry as a surrogate of microglial activation, in mice with two different types of crush injury of the sciatic nerve. We confirmed that incomplete crush of the sciatic nerve (partial crush injury, PCI) resulted in tactile hypersensitivity after the recovery of sensory function (15 days after surgery), whereas the hypersensitivity was not observed after the complete crush (full crush injury, FCI). We observed that immunoreactivity for Iba-1, a microglial marker, was greater in the ipsilateral dorsal horn of lumbar (L4) spinal cord of mice 2 days after FCI compared to PCI, positively correlating with the intensity of crush injury. Ipsilateral Iba-1 reactivity was comparable between injuries at 7 days with a significant increase compared to the contralateral side. By day 15 after injury, ipsilateral Iba-1 immunoreactivity was much reduced compared to day 7 and was not different between the groups. Our results suggest that the magnitude of the early microgliosis is dependent on injury severity, but does not necessarily correlate with the long-term development of chronic pain-like hypersensitivity after peripheral nerve injury.

scholarly journals Presence and activation of pro-inflammatory macrophages are associated with CRYAB expression in vitro and after peripheral nerve injury

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Erin-Mai F. Lim ◽  
Vahid Hoghooghi ◽  
Kathleen M. Hagen ◽  
Kunal Kapoor ◽  
Ariana Frederick ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Sciatic Nerve Crush ◽  
Nerve Crush ◽  
Cytokines And Chemokines ◽  
Inflammatory Macrophages ◽  
Nerve Crush Injury

Abstract Background Inflammation constitutes both positive and negative aspects to recovery following peripheral nerve injury. Following damage to the peripheral nervous system (PNS), immune cells such as macrophages play a beneficial role in creating a supportive environment for regrowing axons by phagocytosing myelin and axonal debris. However, a prolonged inflammatory response after peripheral nerve injury has been implicated in the pathogenesis of negative symptoms like neuropathic pain. Therefore, the post-injury inflammation must be carefully controlled to prevent secondary damage while allowing for regeneration. CRYAB (also known as alphaB-crystallin/HSPB5) is a small heat shock protein that has many protective functions including an immunomodulatory role in mouse models of multiple sclerosis, spinal cord injury, and stroke. Because its expression wanes and rebounds in the early and late periods respectively after PNS damage, and CRYAB null mice with sciatic nerve crush injury display symptoms of pain, we investigated whether CRYAB is involved in the immune response following PNS injury. Methods Sciatic nerve crush injuries were performed in age-matched Cryab knockout (Cryab−/−) and wildtype (WT) female mice. Nerve segments distal to the injury site were processed by immunohistochemistry for macrophages and myelin while protein lysates of the nerves were analyzed for cytokines and chemokines using Luminex and enzyme-linked immunosorbent assay (ELISA). Peritoneal macrophages from the two genotypes were also cultured and polarized into pro-inflammatory or anti-inflammatory phenotypes where their supernatants were analyzed for cytokines and chemokines by ELISA and protein lysates for macrophage antigen presenting markers using western blotting. Results We report that (1) more pro-inflammatory CD16/32+ macrophages are present in the nerves of Cryab−/− mice at days 14 and 21 after sciatic nerve crush-injury compared to WT counterparts, and (2) CRYAB has an immunosuppressive effect on cytokine secretion [interleukin (IL)-β, IL-6, IL-12p40, tumor necrosis factor (TNF)-α] from pro-inflammatory macrophages in vitro. Conclusions CRYAB may play a role in curbing the potentially detrimental pro-inflammatory macrophage response during the late stages of peripheral nerve regeneration.

scholarly journals Possible role of antioxidative capacity of (−)-epigallocatechin-3-gallate treatment in morphological and neurobehavioral recovery after sciatic nerve crush injury

2017 ◽  
Vol 27 (5) ◽  
pp. 593-613 ◽  
Author(s):  
Waleed M. Renno ◽  
Ludmil Benov ◽  
Khalid M. Khan
Keyword(s):  
Spinal Cord ◽  
Sciatic Nerve ◽  
Nerve Injury ◽  
Diameter Ratio ◽  
Crush Injury ◽  
Sciatic Nerve Crush ◽  
Axon Diameter ◽  
Nerve Crush ◽  
Myelin Thickness ◽  
Nerve Crush Injury

OBJECTIVEThis study examined the capacity of the major polyphenolic green tea extract (−)-epigallocatechin-3-gallate (EGCG) to suppress oxidative stress and stimulate the recovery and prompt the regeneration of sciatic nerve after crush injury.METHODSAdult male Wistar rats were randomly assigned to one of 4 groups: 1) Naïve, 2) Sham (sham injury, surgical control group), 3) Crush (sciatic nerve crush injury treated with saline), and 4) Crush+EGCG (sciatic nerve crush injury treated with intraperitoneally administered EGCG, 50 mg/kg). All animals were tested for motor and sensory neurobehavioral parameters throughout the study. Sciatic nerve and spinal cord tissues were harvested and processed for morphometric and stereological analysis. For the biochemical assays, the time points were Day 1, Day 7, Day 14, and Day 28 after nerve injury.RESULTSAfter sciatic nerve crush injury, the EGCG-treated animals (Crush+EGCG group) showed significantly better recovery of foot position and toe spread and 50% greater improvement in motor recovery than the saline-treated animals (Crush group). The Crush+EGCG group displayed an early hopping response at the beginning of the 3rd week postinjury. Animals in the Crush+EGCG group also showed a significant reduction in mechanical allodynia and hyperalgesia latencies and significant improvement in recovery from nociception deficits in both heat withdrawal and tail flick withdrawal latencies compared with the Crush group. In both the Crush+EGCG and Crush groups, quantitative evaluation revealed significant morphological evidence of neuroregeneration according to the following parameters: mean cross-sectional area of axons, myelin thickness in the sciatic nerve (from Week 4 to Week 8), increase of myelin basic protein concentration and gene expression in both the injured sciatic nerve and spinal cord, and fiber diameter to axon diameter ratio and myelin thickness to axon diameter ratio at Week 2 after sciatic nerve injury. However, the axon area remained much smaller in both the Crush+EGCG and Crush groups compared with the Sham and Naïve groups. The number of axons per unit area was significantly decreased in the Crush+EGCG and Crush groups compared with controls. Sciatic nerve injury produced generalized oxidative stress manifested as a significant increase of isoprostanes in the urine and decrease of the total antioxidant capacity (TAC) of the blood from Day 7 until Day 14. EGCG-treated rats showed significantly less increase of isoprostanes than saline-treated animals and also showed full recovery of TAC levels by Day 14 after nerve injury. In spinal cord tissue analysis, EGCG-treated animals showed induced glutathione reductase and suppressed induction of heme oxygenase 1 gene expression compared with nontreated animals.CONCLUSIONSEGCG treatment suppressed the crush-induced production of isoprostanes and stimulated the recovery of the TAC and was associated with remarkable alleviation of motor and sensory impairment and significant histomorphological evidence of neuronal regeneration following sciatic nerve crush injury in rats. The findings of this study suggest that EGCG can be used as an adjunctive therapeutic remedy for nerve injury. However, further investigations are needed to establish the antioxidative mechanism involved in the regenerative process after nerve injury. Only upregulation of glutathione reductase supports the idea that EGCG is acting indirectly via induction of enzymes or transcription factors.

scholarly journals Neuroprotective Effect of Nypa fruticans Wurmb by Suppressing TRPV1 Following Sciatic Nerve Crush Injury in a Rat

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2618
Author(s):  
Mi-Sun Kang ◽  
Gil-Hyun Lee ◽  
Go-Eun Choi ◽  
Hae-Gyung Yoon ◽  
Kyung-Yae Hyun
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Functional Recovery ◽  
Treated Group ◽  
Crush Injury ◽  
Sciatic Nerve Crush ◽  
Neuroprotective Effects ◽  
Nerve Crush ◽  
Nypa Fruticans ◽  
Nerve Crush Injury

Peripheral nerve injury can result in severe functional impairment and decreased quality of life due to loss of sensory and motor function. Nypa fruticans wurmb (NF) has been used in diverse folk remedies in East Asia. We have previously shown that Nypa fruticans wurmb extract has antinociceptive and anti-inflammatory effects by suppressing TRPV1 in the sciatic nerve injury. The present study investigated the effects of NF on the control of TRPV1 in relation to neuroprotective effects of a sciatic nerve crush injury. To evaluate the neuroprotective effects, an animal behavior test and a physiological function test were performed. Functional recovery and nerve recovery were improved in the NF and NF + SB (SB366791; TRPV1 antagonist) treated group. In the histomorphology evaluation, the neuronal regenerative effect of NF on the injured sciatic nerve was confirmed via hematoxylin and eosin (H&E) staining. In this study, the NF and NF + SB treated group showed neuroprotective and functional recovery effects from the sciatic nerve crush injury. Furthermore, the expression of NF-κB and iNOS showed a significantly suppressive effect on NF (p < 0.01), SB (p < 0.01), and NF + SB (p < 0.01) treated group at the 7th and 14th day compared to the vehicle group. This study confirmed the neuroprotective effects of NF on suppressing TRPV1 in a sciatic nerve crush injury. The findings of this study establish the effect of NF as a neurotherapeutic agent to protect the peripheral nerve after a sciatic nerve crush injury.

scholarly journals Catfish Epidermal Preparation Accelerates Healing of Damaged Nerve in a Sciatic Nerve Crush Injury Rat Model

2021 ◽  
Vol 12 ◽  
Author(s):  
Waleed M. Renno ◽  
Mohammad Afzal ◽  
Bincy Paul ◽  
Divya Nair ◽  
Jijin Kumar ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Nerve Injury ◽  
Axonal Regeneration ◽  
Crush Injury ◽  
Male Rats ◽  
Sciatic Nerve Crush ◽  
Spinal Neurons ◽  
Nerve Crush ◽  
Neurobehavioral Deficits ◽  
Nerve Crush Injury

Preliminary investigations showed that preparations from Arabian Gulf catfish (Arius bilineatus, Val) epidermal gel secretion (PCEGS) exhibit potent anti-inflammatory and healing properties as shown in our previous clinical trials for the healing of non-healing diabetic foot ulcers, chronic back pain, and some other neurological disorders. Here, we report for the first time a unique preparation containing only proteins and lipids (soluble protein fraction B, SPF-FB), derived from the PCEGS accelerated the healing and recovery of sensory-motor functions of experimental sciatic nerve crush injury in rats with its unique neuroprotective and neuroregenerative properties on the spinal neurons and peripheral nerve fibers. Male rats were randomly assigned to five groups: (I) NAÏVE, (II) SHAM, (III) CRUSH treated with saline, (IV) CRUSH + SPF-FB treated with 3 mg/kg intraperitoneally (IP) and (V) CRUSH + SPF-FB treated with 6 mg/kg subcutaneously (SC) groups. The crush groups III, IV and V underwent sciatic nerve crush injury, followed by treatment daily for 14 days with saline, SPF-FB IP and SPF-FB SC. All animals were tested for the neurobehavioral parameters throughout the 6 weeks of the study. Sciatic nerve and spinal cord tissues were processed for light and electron histological examinations, stereological analysis, immunohistochemical and biochemical examinations at Week 4 and Week 6 post-injury. Administration of SPF-FB IP or SC significantly enhanced the neurobehavioral sensory and motor performance and histomorphological neuroregeneration of the sciatic nerve-injured rats. The stereological evaluation of the axon area, average axon perimeters, and myelin thickness revealed significant histomorphological evidence of neuroregeneration in the FB-treated sciatic nerve crush injured groups compared to controls at 4 and 6 weeks. SPF-FB treatment significantly prevented the increased in NeuN-immunoreactive neurons, increased GFAP immunoreactive astrocytes, and decreased GAP-43. We conclude that SPF-FB treatment lessens neurobehavioral deficits, enhances axonal regeneration following nerve injury. We conclude that SPF-FB treatment lessens neurobehavioral deficits and enhances axonal regeneration following nerve injury, as well as protects spinal neurons and enhances subcellular recovery by increasing astrocytic activity and decreasing GAP-43 expression.

scholarly journals Ultrasound-guided platelet-rich plasma injection and multimodality ultrasound examination of peripheral nerve crush injury

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Yaqiong Zhu ◽  
Zhuang Jin ◽  
Jing Wang ◽  
Siming Chen ◽  
Yongqiang Hu ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Platelet Rich Plasma ◽  
Blood Platelets ◽  
Crush Injury ◽  
Sciatic Nerve Crush ◽  
Maximal Effect ◽  
Ultrasound Guided ◽  
Nerve Crush ◽  
Nerve Crush Injury

AbstractUltrasound-guided platelet-rich plasma (PRP) injection is able to make up for the limitations of applying a single growth factor. The goal of this study was to investigate the effects of serial ultrasound-guided PRP injections of the appropriate concentration on the treatment of sciatic nerve crush injury, and explore the value of multimodality ultrasound techniques in evaluating the prognosis of crushed peripheral nerve. In vitro, optimal concentration of PRP (from 150%, 250%, 450%, and 650%) was screened due for its maximal effect on proliferation and neurotrophic function of Schwann cells (SCs). In vivo, ninety rabbits were equally and randomly divided into normal control, model, PRP-2.5×, PRP-4.5×, and PRP-6.5× groups. The neurological function and electrophysiological recovery evaluation, and the comparison of the multimodality ultrasound evaluation with the histological results of sciatic nerve crush injury were performed to investigate the regenerative effects of PRP at different concentrations on the sciatic nerve crush injury. Our results showed that the PRP with a 4.5-fold concentration of whole blood platelets could significantly stimulate the proliferation and secretion of SCs and nerve repair. The changes in stiffness and blood perfusion were positively correlated with the collagen area percentage and VEGF expression in the injured nerve, respectively. Thus, serial ultrasound-guided PRP injections at an appropriate concentration accelerates the recovery of axonal function. Multimodality ultrasound techniques provide a clinical reference for prognosis by allowing the stiffness and microcirculation perfusion of crush-injured peripheral nerves to be quantitatively evaluated.

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