Changes In Sciatic Nerve Research Articles

AGMATINE ADMINISTRATION ALLEVIATES NERVE DAMAGE AND IMPROVES NERVE FUNCTION IN METHOTREXATE INDUCED PERIPHERAL NEUROPATHY IN RATS

Objective: Chemotherapeutic agents can produce neurodegenerative changes. This study was conducted to assess the therapeutic potential of agmatine, a neuromodulator, on methotrexate induced neurodegeneration in sciatic nerve. Materials and Methods: 40 male Wistar albino rats were assigned into four groups at random as control, methotrexate, agmatine and methotrexate-agmatine. Methotrexate was injected intraperitoneally at a 37.5 mg/kg/week dose for 3 weeks. Afterwards, agmatine was administered intraperitoneally twice a day at a 40 mg/kg dose for 7 days. Sciatic functional index, nociceptive pain perception and behavioral changes were analyzed every week. Nerve conduction velocity was evaluated. Apoptotic activity and mitophagy, histopathological changes in sciatic nerves were examined. Results: Methotrexate administration resulted in a prolonged escape time to the platform and decreased the time spent in the quadrant in the water maze test; elevated nociceptive latencies; decreased the number of frames passed in the open field test; reduced sciatic NCV and SFI score. Besides, methotrexate administration caused a reduction in myelin thickness and axon diameter in sciatic nerve and a more intense glial fibrillary acidic protein immunoreactivity. Methotrexate administration triggered an increase in the Bax/Bcl-2 protein expression ratio without changing the expression level of Parkin, indicating a slight apoptotic activation. agmatine administration improved methotrexate induced changes in behavioral performances, nociceptive pain perception, nerve conduction, SFI scores and histopathological changes. Conclusion: Agmatine has been demonstrated to possess a therapeutic potential in methotrexate induced degeneration and peripheral neuropathy in the rat sciatic nerve.

Discussion on the relationship between pathological changes of sciatic nerve and Sarm1 protein expression in rats with n-hexane poisoning

Objective: To explore the potential evidence of active peripheral nerve necrosis when n-hexane produces toxic effects on peripheral nerves. Methods: In May 2023, 36 SPF grade SD male rats with a body weight of 200-220 g were divided into 4 groups with 9 rats in each group and given normal saline and different doses of n-hexane (168, 675, 2 700 mg/kg) by gavage for 6 consecutive weeks (5 days/week). Three rats in each group were killed at the 2nd, 4th and 6th week, respectively. The spinal cord to sciatic nerve tissue was broken and the supernatant was extracted for SDS-PAGE protein isolation. The expression level of Sarm1 protein was analyzed with the β-Actin color strip of internal reference protein by Western blot. The expression of Sarm1 protein was analyzed by the gray ratio of the two. At the 6th week, the sciatic nerve sections of the each group were observed by light microscope and electron microscope. Results: The number of axons was obviously reduced by light microscopy. According to electron microscope, myelin lesions were mainly local disintegration, deformation, and different thickness. The deformation of axonal surface became smaller. The axons in the nerve bundle membrane showed degeneration and reduction. The gray ratio of Sarm1 protein and internal reference protein bands in each group had no significant change at the second week of exposure, and the ratio of SARM1 protein to internal reference protein bands was 1.47 in the high dose group at the fourth week, and 1.51 and 1.89 in the middle and high dose group at the sixth week, respectively. Conclusion: Waller's degeneration was observed in sciatic neuropathologic manifestations of n-hexane-poisoned rats, and the expression level of Sarm1 protein increased.

Compound Qiying Granules alleviates diabetic peripheral neuropathy by inhibiting endoplasmic reticulum stress and apoptosis

BackgroundDiabetic peripheral neuropathy (DPN) is a major complication of diabetes. This study aimed to investigate the therapeutic effects and molecular mechanisms of Compound Qiying Granules (CQYG) for DPN.MethodsRats and RSC96 cells of DPN models were established to evaluate the therapeutic effects of CQYG. Then the morphology and apoptotic changes of sciatic nerves were detected. Further, tandem mass tag based quantitative proteomics technology was used to identify differentially expressed proteins (DEPs) and the underlying molecular mechanisms. Protein expression of key signaling pathways was also detected.ResultsCQYG treatment significantly improved blood glucose and oxidative stress levels, and further reduced nerve fiber myelination lesions, denervation, and apoptosis in DPN rats. Further, 2176 DEPs were found in CQYG treated DPN rats. Enrichment analysis showed that protein processing in the endoplasmic reticulum (ER), and apoptosis were all inhibited after CQYG treatment. Next, CQYG treatment reduced inflammatory factor expression, mitochondrial damage, and apoptosis in RSC96 cells which induced by high glucose. Transmission electron microscopy results found that CQYG treatment improved the morphology of nerve myelin, mitochondria, and ER. CQYG treatment decreased ER stress and apoptosis pathway proteins that were highly expressed in DPN models. In addition, we also predicted the potential targets of CQYG in DEPs.ConclusionsCQYG exerts neuroprotective effects in experimental diabetic neuropathy through anti-ER stress and anti-apoptosis.

The effects of voluntary exercise on histological and stereological changes of sciatic nerve, nitric oxide levels, and peripheral neuropathy caused by high-fat diet-induced type 2 diabetes in male rats

This research was conducted to investigate the possible beneficial impacts of voluntary exercise on sciatic tissue, nitric oxide levels, stereological changes, and peripheral neuropathy caused by "high-fat-diet (HFD)"-induced "type 2 diabetes mellitus (T2DM)" in male rats. Rats were put into four experimental groups at random: "healthy control (C), voluntary exercise (VE), diabetic (D), and diabetic rats treated by voluntary exercise (VED)"; each group contain eight animals. Animals in VE and VED groups performed "voluntary exercise (VE)" for ten weeks. Animals in D and VED groups became diabetic after receiving a HFD for four weeks and an intraperitoneal injection (IP) of "streptozotocin (STZ)" (35 mg/kg). In order to evaluate mechanical and thermal algesia, hot plate, tail withdrawal, and von Frey tests were carried out. At the end of this study, serum NOx levels were assessed, and histological and stereological analyses were conducted. Mechanical nociceptive thresholds indicated considerable reduction (p < 0.001) which was followed by a remarkable enhance (p < 0.001) in thermal nociceptive threshold of D group. Tissue changes were also seen in sciatic nerve of D group. Voluntary exercise modified thermal and mechanical sensitivity in diabetic rats. It also improved the damaged sciatic nerve in diabetic animals.

Structural Study of the Sciatic Nerve in Diabetic RafsTreated with Alium Sativurn

The diabetes mellitus has been induced in Sprague Dawely rats, by injection of alloxan 75 mg/ kg body weight, once daily for three successive days. Group of diabetic rats were treated with oral hyopgycemic (Glibenclamide) drug only and another group was treated with oral hyopgycemic (Glibenclamide) drug and Alium Sativum- garlic powder (250 mg / kg body weight, daily. Histological and histometric changes of sciatic nerve were investigated, by applying routine histological stains with specific application of osmium tetroxide for staining the nerve, detecting the structural changes and to measuring the improvement in the regeneration of the sciatic nerves. It has been found that the Alium Sativum treated group restored to certain degree the normal architectures of the sciatic nerve in diabetic rats and the improvement in thermal sensation as compared with non treated group or group treated with oral hypgycemic drug only.

The role of hesperidin in ameliorating the histological changes of sciatic nerve in streptozotocin-induced diabetic rats: Light and electron microscopic study

The role of hesperidin in ameliorating the histological changes of sciatic nerve in streptozotocin-induced diabetic rats: Light and electron microscopic study

Neuropathologic damage induced by radiofrequency ablation at different temperatures &amp;ndash; An Experimental Study

&lt;p&gt;&lt;strong&gt;Background and Objective:&lt;/strong&gt; Radiofrequency ablation is a safe and less invasive technique that uses an electric current to damage nerve tissue to stop it from sending pain signals. This study was aimed to determine the molecular mechanism of neuropathologic damage induced by radiofrequency ablation at different temperatures.&lt;/p&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;A total of 36 Sprague Dawley (SD) rats were used as model with neuropathological injury. These rats were divided into 6 groups based on temperature stimulation at 42℃, 47℃, 52℃, 57℃, 62℃ and 67℃. Conduction time, distance and velocity were recorded after thermal injury. Hematoxylin and eosin (H&amp;amp;E) staining was used to observe the histopathological changes of sciatic nerve. Neural ion channel proteins such as Sodium voltage-gated channel alpha subunit 9 (SCN9A), Sodium channel B3 subunit (SCN3B) and Neurofascin (NFASC) expression &amp;nbsp;in sciatic nerve tissue was &amp;nbsp;detected by Western Blot.&lt;/p&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Results:&lt;/strong&gt; Nerve conduction velocity gradually decreased with the increase in temperature and neuronal damage was seen at 67℃. H&amp;amp; E staining showed increased degeneration of neurons with an increase in temperature from 47℃ to 67℃. SCN9A and SCN3B expression at 57℃, 62℃, and 67℃ was much higher however, NFASC expression was lower at the same temperatures.&lt;/p&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Conclusion:&lt;/strong&gt; Neuropathological damage caused by RFA at different temperatures shows&amp;nbsp; &amp;nbsp;positive correlation with nerve conduction velocity. Heat transfer injury affects the expression of SCN9A, SCN3B and NFASC in sciatic nerve tissue.&lt;/p&gt;

Quercetin reduces inflammation in a rat model of diabetic peripheral neuropathy by regulating the TLR4/MyD88/NF-κB signalling pathway

Neuroinflammation contributes significantly to the pathogenesis of diabetic peripheral neuropathy (DPN). Quercetin reportedly exerts neuroprotective effects in DPN. Here, we aimed to evaluate the potential anti-inflammatory effects of quercetin in a DPN rat model. Eight weeks after streptozotocin administration, diabetic rats were treated with quercetin (30 and 60 mg/kg/day orally) for 6 weeks. We assessed the mechanical withdrawal threshold (MWT), nerve conduction velocity (NCV) and morphological changes in sciatic nerves. Additionally, we measured the levels of tumour necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-6 by ELISA and the expression of TLR4, MyD88, and NF-κB in sciatic nerves by western blotting and immunohistochemical assays. Our results revealed that blood glucose levels and body weight were unaltered following quercetin treatment. However, quercetin improved MWT (p < 0.05), NCV (p < 0.05), and pathological changes in the sciatic nerves of DPN rats. Quercetin significantly alleviated the increased expression of TNF-α (p < 0.05) and IL-1β (p < 0.001). Furthermore, high-dose quercetin administration significantly downregulated the expression of TLR4 (p < 0.001), MyD88 (p < 0.001), and NF-κB (p < 0.001) in sciatic nerves of DPN rats. Our findings revealed that quercetin could reduce the levels of inflammatory factors in DPN rats, possibly mediated via the downregulation of the TLR4/MyD88/NF-κB signalling pathway. Collectively, these results suggest that although quercetin did not decreased blood glucose levels or reversed the reduced body weight, it showed anti-inflammatory and neuroprotective effects, which was beneficial for the treatment of DPN.

ОЦЕНКА АНТИНОЦИЦЕПТИВНОГО ДЕЙСТВИЯ МЕЗЕНХИМАЛЬНЫХ СТВОЛОВЫХ КЛЕТОК ЖИРОВОЙ ТКАНИ ПРИ ЭКСПЕРИМЕНТАЛЬНОЙ ПЕРИФЕРИЧЕСКОЙ НЕЙРОПАТИЧЕСКОЙ БОЛИ

Objective. To estimate an anti-nociceptive and regenerative potential of adipose-derived mesenchymal stem cells in experimental post-traumatic neuropathy in rats. Methods. Neuropathic pain was induced by axotomy technique in rat left hind paw (Wistar rats (n=113)). The respective group of subjects received ADMSCs dose of 1×10&lt;sup&gt;6&lt;/sup&gt; cells/kg and 2×10&lt;sup&gt;6&lt;/sup&gt; cells/kg into the site of sciatic nerve injury at 2 regimens: single (7&lt;sup&gt;th&lt;/sup&gt; day post-surgery) and twice (7&lt;sup&gt;th&lt;/sup&gt; and 14&lt;sup&gt;th&lt;/sup&gt; day post-surgery). Nociceptive responses, as well as histological changes of sciatic nerve and perineural tissue were assessed in dynamics. Results. Sciatic nerve axotomy led to a significant increase of mechanical nociceptive sensitivity of ipsilateral hind paw by 7&lt;sup&gt;th&lt;/sup&gt; day, as well as to fibrotic changes of peri- and epineural areas of damaged nerve fibers and to denervation of surrounding muscle tissue and fascia. Local administration of ADMSCs effectively abolished mechanical hyperalgesia by 14&lt;sup&gt;th&lt;/sup&gt; day after first injection at all regimens tested. Among tested regimens, the most pronounced anti-nociceptive and regenerative effects were induced by single injection of ADMSCs (1×10&lt;sup&gt;6&lt;/sup&gt; cells/kg). As the dose and frequency of ADMSCs administration elevated, their reparative and anti-inflammatory properties reduced. Conclusion. Obtained results testify anti-nociceptive potential of ADMSCs and feasibility of its further investigation on the experimental models of neuropathy. What this paper adds For the first time the impact of different regimen of allogenic adipose-derived mesenchymal stem cells (ADMSCs) transplantation on nociceptive sensitivity and microstructure changes of sciatic nerve in rats with peripheral neuropathy has been studied. Allogenic transplantation of mesenchymal stem cells at a dose of 1×10&lt;sup&gt;6&lt;/sup&gt; cells/kg has been found out to exhibit the most powerful anti-nociceptive and regenerative effects with a single local injection confirmed by algometry and histological study.

Morphological and hemodynamic changes of sciatic nerves and their vasa nervorum during circular compression and relaxation

The main aim of this study was to evaluate the biomechanical and hemodynamic responses of vasa nervorum under transverse circular compression. In situ compress-and-hold experiments were performed on the sciatic nerves of healthy and diabetic rats, and the blood flow within the vasa nervorum was observed using Doppler-optical coherence tomography. A new technique was developed to obtain the time-course of the cross sectional area and the morphology of the vasa nervorum from the tomographic images. A quasi-linear viscoelastic model was used to investigate the overall biomechanical properties of the nerves, and a two-dimensional three-layered finite element model was constructed to analyze the distribution of stress and the morphological changes during the compression-relaxation process.The results showed that the lumenal area of vasa nervorum was reduced in the compression stage, especially for the diabetic nerves. The reduction was greater than 70% when the reduction of the nerve diameter was only 10%. The quasi-linear viscoelastic model showed that normal nerves were more elastic but less viscous than the diabetic nerves. The finite element analyses demonstrated that perineurium could sustain more stress than other layers, while epineurium served as a cushion to protect vasa nervora. In addition, there were regions within epineurium with less stress, so that vasa nervora in these saddle regions were less deformed. The vasa nervorum in diabetic rats was more prone to compression and reduction of blood flow than that of the normal rats. The histological studies supported the simulation results.

Quantitative assessment of sciatic nerve changes in Charcot–Marie–Tooth type 1A patients using magnetic resonance neurography

Nerve tissue alterations have rarely been quantified in Charcot-Marie-Tooth type 1A (CMT1A) patients. The aim of the present study was to quantitatively assess the magnetic resonance imaging (MRI) anomalies of the sciatic and tibial nerves in CMT1A disease using quantitative neurography MRI. It was also intended to seek for correlations with clinical variables. Quantitative neurography MRI was used in order to assess differences in nerve volume, proton density and magnetization transfer ratio in the lower limbs of CMT1A patients and healthy controls. Disease severity was evaluated using the Charcot-Marie-Tooth Neuropathy Score version 2, Charcot-Marie-Tooth examination scores and Overall Neuropathy Limitations Scale scores. Electrophysiological measurements were performed in order to assess the compound motor action potential and the Motor Unit Number Index. Clinical impairment was evaluated using muscle strength measurements and Charcot-Marie-Tooth examination scores. A total of 32 CMT1A patients were enrolled and compared to 13 healthy subjects. The 3D nerve volume, magnetization transfer ratio and proton density were significantly different in CMT1A patients for the whole sciatic and tibial nerve volume. The sciatic nerve volume was significantly correlated with the whole set of clinical scores whereas no correlation was found between the tibial nerve volume and the clinical scores. Nerve injury could be quantified in vivo using quantitative neurography MRI and the corresponding biomarkers were correlated with clinical disability in CMT1A patients. The sensitivity of the selected metrics will have to be assessed through repeated measurements over time during longitudinal studies to evaluate structural nerve changes under treatment.

Experimental study on autologous injectable platelets rich fibrin combined with bone mesenchymal stem cells in treating sciatic nerve injury in rats

To investigate the effectiveness of autologous injectable platelet rich fibrin (i-PRF) combined with bone marrow mesenchymal stem cells (BMSCs) for sciatic nerve injury in rats. BMSCs were isolated and cultured from tibial bone marrow of Sprague Dawley (SD) neonatal rats aged 10-15 days and passaged to the 4th generation. i-PRF was prepared from posterior orbital venous blood of adult SD rats by improved low-speed centrifugation. Twenty-four adult SD rats were selected and randomly divided into 4 groups with 6 rats in each group after the sciatic nerve Ⅲ degree injury model was established by modified crush injury method. Groups A, B, C, and D were injected with BMSCs suspension+autologous i-PRF, autologous i-PRF, BMSCs suspension, and normal saline, respectively. The Basso-Beattie-Bresnahan (BBB) score was used to evaluate the recovery of neurological function of the affected limb of rats every week from 1 to 8 weeks after operation. At 2 months after operation, the rats were sacrificed and the histological changes of sciatic nerve were observed by HE staining. The microstructural changes of nerve fibers, myelin sheath, and nucleus were observed by transmission electron microscope. The expressions of N-cadherin, Nestin, and glial fibrillary acidic protein (GFAP) were detected by Western blot. No immune rejection or death occurred in the rats after operation. There was no significant difference in BBB scores between groups at 1 week after operation ( P>0.05); at 2-8 weeks after operation, BBB scores in group A were significantly higher than those in groups B, C, and D, and in groups B, C than in group D ( P<0.05), there was no significant difference between groups B and C ( P>0.05). HE staining showed that the nerve fibers in group A arranged in order, without defect or demyelination; the nerve fibers in group B were not clear and slightly swollen; some of the nerve fibers in group C were disordered and demyelinated; the nerve fibers in group D were not continuous, obviously demyelinated, and some of the nerve adventitia damaged. Transmission electron microscope showed that the structure of nerve fibers in group A was clear, myelin sheath was complete, and nucleus was dense; group B was slightly less than group A; group C had fuzzy structure, demyelination, and hollowing out; group D had disorder structure, demyelination, and hollowing out, and the middle part of nerve adventitia continuity. Western blot detection results showed that there was no significant difference in the relative expression of Nestin between groups ( P>0.05). The relative expression of N-cadherin was significantly lower in groups B, C, and D than in group A, in groups C and D than in group B, and in group D than in group C ( P<0.05). The relative expression of GFAP was significantly lower in groups B, C, and D than in group A, in group D than in groups B and C ( P<0.05); there was no significant difference between groups B and C ( P>0.05). Autologous i-PRF combined with BMSCs can effectively treat sciatic nerve tissue injury in rats.

Haematoxylon campechianum Extract Ameliorates Neuropathic Pain via Inhibition of NF-κB/TNF-α/NOX/iNOS Signalling Pathway in a Rat Model of Chronic Constriction Injury.

In this study, the phytochemical composition and the possible prophylactic effects of an aqueous ethanol extract of Haematoxylon campechianum flowers (HCF) on peripheral neuropathic pain in a chronic constriction injury (CCI) rat model are investigated. Rats with induced CCI were subjected to neuropathic pain behaviour tests and evaluated by chemical, thermal, and mechanical sensation tests and functional recovery of the brain stem and sciatic nerve at 7- and 14-day intervals. The effect of the extract on acute pain and inflammation is also investigated. The extract exerted both peripheral and central analgesic and anti-inflammatory properties in addition to antipyretic effects that are clear from targeting COX, LOX and PGE. It was found that CCI produced significant thermal and mechanical hyperalgesia, cold allodynia and deleterious structural changes in both sciatic nerve and brain stem. Treatments with HCF extract significantly improved cold and thermal withdrawal latency, mechanical sensibility and ameliorated deleterious changes of sciatic nerve and brain stem at different dose levels. The extract also ameliorated oxidative stress and inflammatory markers in brain stem and sciatic nerve. It suppressed the apoptotic marker, p53, and restored myelin sheath integrity. The effects of HCF extract were more potent than pregabalin. Fifteen secondary metabolites, mainly gallotannins and flavonoids, were characterized in the extract based on their retention times and MS/MS data. The identified phenolic constituents from the extract could be promising candidates to treat neuropathic pain due to their diverse biological activities, including antioxidant, anti-inflammatory and neuroprotective properties.

Sciatic Nerve Structural and Functional Recovery with Extract of Phyllanthus amarus and Esculetin in STZ-Induced Hyperglycemic Rats.

Background: Diabetes-instigated nerve damage is a chronic complication including impaired peripheral nerve function with lowered nerve conduction velocity (NCV), demyelination of nerve fibres and alterations in the behaviour. Many clinical and experimental studies have proved that Phyllanthus amarus and esculetin have potential effects against various diseases.Purpose: The aim of this study is to assess the neuroprotective role of hydro-ethanolic extract of Phyllanthus amaras (PAE) and esculetin (ESC) on NCV, metabolism, behavioural and structural changes in diabetic rats.Methods: The extent of protection using PAE and ESC in diabetic rats was determined by checking the HbA1c, NO, myeloperoxidase (MPO), total calcium, protein content, Na+-K+ ATPase activity, acetylcholine content and behavioural alterations using rotarod and maze learning tests on 7, 14 and 21 days. NCV was measured on the 21st day.Results: The diabetic rats showed increased HbA1c, nitrite, MPO, calcium and decreased protein, Na+-K+ ATPase activity, NCV, acetylcholine, behavioural alterations and morphological changes of sciatic nerve so that diabetic peripheral neuropathy (DPN) is manifested. Continuous treatment for three weeks with Phyllanthus amarus and esculetin significantly minimized the damage to axons and myelin sheath and enhanced the sciatic NCV by reversing all the mentioned parameters.Conclusion: Phyllanthus amarus and esculetin showed the anti-diabetic as well as anti-inflammatory characteristics by prevention of initiation of adverse processes of the sciatic nerve morphology, internal cell functions leading to improved coordination, behavioural and physiological functions in STZ-induced diabetic rats. PAE has shown similar effects with the ESC. However, further studies are essential to confirm their detailed therapeutic effects.

The Effect of Long Term Administration of Aspartame on the Sciatic nerve of adult male albino rats and the Possible Therapeutic Role of Ozone (Histological and Biochemical Study)

Introduction: Aspartame is a widely used artificial non-nutritive sweetener, which replaced sucrose in foods for enhancing flavor while reducing calories. It was confirmed that aspartame was a multipotential carcinogenic agent increases the risk of lymphoma and neurological tumors.Aim of the work: This work is aimed to evaluate the effect of aspartame on the structure of the sciatic nerve and the possible role of ozone therapy.Material and methods: The present study was carried out on 30 adult male wister albino rats divided into three groups: control (I), aspartame(II) and ozone and aspartame treated (III) groups. Group (II) received aspartame (250 mg/kg/d) dissolved in distilled water and administered by gastric tube for 3 months. Group (III) received aspartame as in Group II, then received an ozone dose of 1.1 mg/kg/d intraperitoneal (IP) for 30 days. Rats were anesthetized and sciatic nerves were processed for light, electron microscope, morphometric and Real time-PCR analysis.Results: The sciatic nerve of aspartame group showed loss of regular architecture, separation of myelin lamellae with splitting of myeline sheath. Schwann cells appeared with vacuolated cytoplasm and collagen fibrils could be seen in the endoneurium. Immunohistochemically, there was decrease in expression of myeline basic protein (MBP) in myeline sheath and decrease in axon/fiber ratio (g ratio) statistically. Apparent structural and histomorphological improvement were noticed in ozone group.Conclusion: Aspartame induced histopathological changes in sciatic nerve. Our data suggests that ozone therapy has an important role in sciatic nerve regeneration by increasing the expression of neurotrophic and angiogenic factors establishing more favorable environment for nerve regeneration.

Effect of low-level 1800 MHz radiofrequency radiation on the rat sciatic nerve and the protective role of paricalcitol.

The nervous system is an important target of radiofrequency (RF) radiation exposure since it is the excitable component that is potentially able to interact with electromagnetic fields. The present study was designed to investigate the effects of 1,800 MHz RF radiation and the protective role of paricalcitol on the rat sciatic nerve. Rats were divided into four groups as control, paricalcitol, RF, and RF + paricalcitol. In RF groups, the rats were exposed to 1,800 MHz RF for 1 h per day for 4 weeks. Control and paricalcitol rats were kept under the same conditions without RF application. In paricalcitol groups, the rats were given 0.2 μg/kg/day paricalcitol, three times per week for 4 weeks. Amplitude and latency of nerve compound action potentials, catalase activities, malondialdehyde (MDA) levels, and ultrastructural changes of sciatic nerve were evaluated. In the RF group, a significant reduction in amplitude, prolongation in latency, an increase in the MDA level, and an increase in catalase activity and degeneration in the myelinated nerve fibers were observed. The electrophysiological and histological findings were consistent with neuropathy, and the neuropathic changes were partially ameliorated with paricalcitol administration. Bioelectromagnetics. 39:631-643, 2018. © 2018 Wiley Periodicals, Inc.

Biochemical changes in injured sciatic nerve of rats after low-level laser therapy (660nm and 808nm) evaluated by Raman spectroscopy.

The aim of this study was to identify biochemical changes in sciatic nerve (SN) after crush injury and low-level laser therapy (LLLT) with 660nm and 808nm by Raman spectroscopy (RS) analysis. A number of 32 Wistar rats were used, divided into four groups (control 1, control 2, LASER 660nm, and LASER 808nm). All animals underwent surgical procedure of the SN and groups control 2, LASER 660nm, and LASER 808nm were submitted to SN crush damage (axonotmesis). The LLLT in the groups LASER 660nm and LASER 808nm was applied daily for 21 consecutive days (100mW, 30s, 133J/cm2 fluence). The hind paw was removed and the SN was dissected and positioned on an aluminum support to collect dispersive Raman spectra (830nm excitation, 30s accumulation). To estimate the biochemical changes in the SN associated with LLLT, the principal component analysis (PCA) was applied. The Raman spectra of the sciatic nerve fragments showed peaks of the major biochemical components of the nerve, especially sphingolipids, phospholipids, glycoproteins, and collagen. The spectral features identified in some of the principal component loading vectors are referred to the biochemical elements present on the SN and were increased in the groups treated with LLLT, mainly lipids (sphingo and phospholipids) and proteins (collagen)-constituents of the myelin sheath. The RS was effective in identifying the biochemical differences in the SN after the crush injury, and LASER 660nm was more efficient than the LASER 808nm in cell proliferation and repair of the injured SN.

Unpublished Neuropathologic Mechanism Behind the Muscle Weakness/Paralysis and Gait Disturbances Induced by Sciatic Nerve Degeneration After Spinal Subarachnoid Hemorrhage: An Experimental Study

Adamkiewicz arteries vasospasm in spinal cord subarachnoid hemorrhage (SAH) can affect the spinal cord. Although muscle dysfunction of extremities is a common problem after spinal cord ischemia induced by SAH, to our knowledge there are no studies on degenerative changes in peripheral nerves. We studied the histopathologic changes in sciatic nerves after spinal SAH. This study was carried out on 19 rabbits. Five of them were used as control animals, 5 were in the sham group, and 9 were in the study group. For the procedure, 0.5 cm3 of serum saline for the sham group and autologous arterial blood for the study group was injected into the lumbar subarachnoid space at the L5 level. After 2 weeks of follow-up, the sciatic nerve roots at the L5-S3 levels with spinal cords and sciatic nerves were bilaterally extracted to the levels of the collum femoris. The specimens were evaluated by stereologic methods, and degenerated sciatic nerve axons were estimated by Cavalieri methods. Kruskal-Wallis and Mann-Whitney U tests were used for data analysis. Differences of P < 0.005 were evaluated as significant. The mean number of degenerated axon density per square millimeter of sciatic nerve at the collum femoris level was 7 ± 2/mm2 in the control group, 23 ± 7/mm2 in the sham group (P < 0.005), and 125 ± 32/mm2 in the SAH group (P < 0.00005). Statistical analysis showed that spinal SAH may cause axonal degeneration in the peripheral nerves. We concluded that SAHs frequently affect the spinal cord and result in axonal injury to peripheral nerves, of which there is no mention in the literature.

Role of interleukin-17 in peripheral nerve in blood-nerve barrier injury in a rat model of neuropathic pain

Objective To evaluate the role of interleukin-17 (IL-17) in the peripheral nerve in blood-nerve barrier injury in a rat model of neuropathic pain(NP). Methods Forty healthy adult male Sprague-Dawley rats, weighing 250-280 g, were divided into 4 groups (n=10 each) using a random number table method: sham operation group(Sham group), NP group, blank vector group (BV group) and IL-17 siRNA recombinant lentivirus group (siRNA group). The rats were anesthetized with chloral hydrate, and intrathecal catheters were implanted.NP was produced by chronic constriction injury (CCI) to the sciatic nerve.Normal saline 10 μl was intrathecally injected at day 3 after CCI in Sham and NP groups.Blank vector and IL-17 siRNA-GFP recombinant lentivirus 1×107 TU 10 μl were intrathecally injected, and then the tube was washed using normal saline 10 μl with the total volume of 20 μl once a day for 4 consecutive days.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured on day 1 before CCI and days 1, 7, 10, 11, 12, 13 and 14 after CCI.Animals were sacrificed after the last behavior testing, and a segment of injured sciatic nerve 7 mm in length and containing 3 ligatures were harvested for examination of the ultrastructure and for detection of the expression of IL-17, occludin and claudin-5 by Western blot. Results Compared with Sham group, the MWT was significantly decreased, TWL was shortened, the expression of IL-17 was up-regulated, and the expression of occludin and claudin-5 was down-regulated at each time point after CCI in the other groups (P<0.05 or 0.01). Compared with NP group or with BV group, the MWT was significantly increased, TWL was prolonged, the expression of IL-17 was down-regulated, the expression of occludin and claudin-5 was up-regulated (P<0.05), and the pathological changes of sciatic nerve were significantly attenuated in siRNA group. Conclusion The mechanism of blood-nerve barrier injury may be related to increased level of IL-17 in the peripheral nerve in a rat model of NP. Key words: Interleukin-17; Neuralgia; Blood-nerve barrier

Toxic effect of acetamiprid on Rana ridibunda sciatic nerve (electrophysiological and histopathological potential)

In this study, the effects of a neonicotinoid insecticide acetamiprid on the sciatic nerve of Rana ridibunda were investigated by using electrophysiological and histological methods. A total of 35 preparations of sciatic nerve isolated from 35 frogs (Nervus ischiadicus) were used in the experiments. Experiments were designed as four different dose groups (n = 8 per group). Acetamiprid solutions of 1 (group 1), 10 (group 2), 100 (group 3), and 1000 µM (group 4) were applied to the nerves in dose groups. In each group, action potentials were recorded before application of acetamiprid which served as control data. The extracellular action potentials were recorded for each group of 30th, 60th, 90th and 120th min of application time. Action potential amplitude and area were measured from recordings. Histological evaluation was performed by transmission electron microscopy.In electrophysiological examination, all doses in which acetamiprid applied have shown the effect from the 30th min and suppressed the sciatic nerve action potential. Acetamiprid significantly reduced the amplitude at the rate of 78–96% and the area at the rate of 79–98% (p < 0.05). In electron microscopic examination, the control nerves were in normal appearance. Disorganization, irregularity, dense ovoid body formation, fragmentation of the myelin sheath, and loss on some axoplasm of the nerves in the dose group have been observed. Our findings showed that acetamiprid can cause neuropathic changes in sciatic nerve at all applied doses. These results indicate that acetamiprid as other insecticides can have harmful effects on non-target organisms.