Overexpression of GDNF in the Uninjured DRG Exerts Analgesic Effects on Neuropathic Pain Following Segmental Spinal Nerve Ligation in Mice

2011 ◽  
Vol 12 (11) ◽  
pp. 1130-1139 ◽  
Author(s):  
Kumiko Takasu ◽  
Atsushi Sakai ◽  
Hideki Hanawa ◽  
Takashi Shimada ◽  
Hidenori Suzuki
2014 ◽  
Vol 121 (2) ◽  
pp. 362-371 ◽  
Author(s):  
Masafumi Kimura ◽  
Hideaki Obata ◽  
Shigeru Saito

Abstract Background: Morphine produces powerful analgesic effects against acute pain, but it is not effective against neuropathic pain, and the mechanisms underlying this reduced efficacy remain unclear. Here, the authors compared the efficacy of systemic morphine between normal rats and rats with peripheral nerve injury, with a specific focus on descending serotonergic mechanisms. Methods: After L5 spinal nerve ligation injury, male Sprague–Dawley rats were subjected to behavioral testing, in vivo microdialysis of the spinal dorsal horn to determine serotonin (5-hydroxytryptamine [5-HT]) and noradrenaline release, and immunohistochemistry (n = 6 in each group). Results: Intraperitoneal administration of morphine (1, 3, or 10 mg/kg) produced analgesic effects in normal and spinal nerve ligation rats, but the effects were greater in normal rats (P < 0.001). Morphine increased 5-HT release (450 to 500% of the baseline), but not noradrenaline release, in the spinal dorsal horn via activation of serotonergic neurons in the rostral ventromedial medulla. Intrathecal pretreatment with ondansetron (3 μg), a 5-HT3 receptor antagonist, or 5,7-dihydroxytryptamine creatinine sulfate (100 μg), a selective neurotoxin for serotonergic terminals, attenuated the analgesic effect of morphine (10 mg/kg) in normal rats but increased the analgesic effect of morphine in spinal nerve ligation rats (both P < 0.05). Conclusions: Systemic administration of morphine increases 5-HT levels in the spinal cord, and the increase in 5-HT contributes to morphine-induced analgesia in the normal state but attenuates that in neuropathic pain through spinal 5-HT3 receptors. The plasticity of the descending serotonergic system may contribute to the reduced efficacy of systemic morphine in neuropathic pain.


Nanomedicine ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. 1113-1126
Author(s):  
Thuỳ Linh Phạm ◽  
Yuhua Yin ◽  
Hyeok Hee Kwon ◽  
Nara Shin ◽  
Song I Kim ◽  
...  

Aims: We investigated whether miRNA (miR) 146a-5p-loaded nanoparticles (NPs) can attenuate neuropathic pain behaviors in the rat spinal nerve ligation-induced neuropathic pain model by inhibiting activation of the NF-κB and p38 MAPK pathways in spinal microglia. Materials & methods: After NP preparation, miR NPs were assessed for their physical characteristics and then injected intrathecally into the spinal cords of rat spinal nerve ligation rats to test their analgesic effects. Results: miR NPs reduced pain behaviors for 11 days by negatively regulating the inflammatory response in spinal microglia. Conclusion: The anti-inflammatory effects of miR 146a-5p along with nanoparticle-based materials make miR NPs promising tools for treating neuropathic pain.


Author(s):  
Mohammad Ali Zabihian ◽  
Mehdi Hosseini ◽  
Farideh Bahrami ◽  
Maryam Iman ◽  
Maedeh Ghasemi ◽  
...  

Abstract Objectives Resveratrol as a natural polyphenolic agent can alleviate neuropathic pain symptoms. The mechanism of analgesic activity of resveratrol is far from clear. The current study examine whether analgesic activity of resveratrol is mediated by its neuroprotective and anti-oxidant activity in the neuropathic pain. We further examine whether analgesic activity of resveratrol is mediated by β-adrenoceptors in the brain. Methods Neuropathic pain induced by L5 spinal nerve ligation (SNL). Male Wistar rats assigned into sham, SNL, SNL + resveratrol (40 μg/5 μL), and SNL + resveratrol + propranolol (a non-selective β-adrenoceptor antagonist, 30 μg/5 μL) groups. Drugs injected intracerebroventricular (ICV) at day SNL surgery and daily for 6 days following SNL. Thermal allodynia and anxiety examined on days of −1, 2, 4, and 6 following SNL. Electrophysiological study performed on day 6 following SNL for evaluation of resveratrol effects on sciatic nerve conduction velocity (NCV). The activity of catalase (Cat) and superoxide dismutase (SOD) enzymes in the brain assessed on days 6 following SNL. Results Resveratrol significantly decreased thermal allodynia (and not anxiety) in all experimental days. Additionally, resveratrol significantly increased NCV, and also normalized the disrupted Cat and SOD activities following neuropathic pain. Furthermore, propranolol significantly blocked the analgesic and neuroprotective effects of resveratrol. Conclusions It is suggested that the analgesic effects of resveratrol is mediated by its neuroprotective and antioxidant activities in the neuropathic rats. Furthermore, propranolol blocked the analgesic and neuroprotective effects of resveratrol.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Takayuki Seto ◽  
Hidenori Suzuki ◽  
Tomoya Okazaki ◽  
Yasuaki Imajo ◽  
Norihiro Nishida ◽  
...  

Abstract Background The spinal nerve ligation (SNL) rat is well known as the most common rodent model of neuropathic pain without motor deficit. Researchers have performed analyses using only the von Frey and thermal withdrawal tests to evaluate pain intensity in the rat experimental model. However, these test are completely different from the neurological examinations performed clinically. We think that several behavioral reactions must be observed following SNL because the patients with neuropathic pain usually have impaired coordination of the motions of the right–left limbs and right–left joint motion differences. In this study, we attempted to clarify the pain behavioral reactions in SNL rat model as in patients. We used the Kinema-Tracer system for 3D kinematics gait analysis to identify new characteristic parameters of each joint movement and gait pattern. Results The effect of SNL on mechanical allodynia was a 47 ± 6.1% decrease in the withdrawal threshold during 1–8 weeks post-operation. Sagittal trajectories of the hip, knee and ankle markers in SNL rats showed a large sagittal fluctuation of each joint while walking. Top minus bottom height of the left hip and knee that represents instability during walking was significantly larger in the SNL than sham rats. Both-foot contact time, which is one of the gait characteristics, was significantly longer in the SNL versus sham rats: 1.9 ± 0.15 s vs. 1.03 ± 0.15 s at 4 weeks post-operation (p = 0.003). We also examined the circular phase time to evaluate coordination of the right and left hind-limbs. The ratio of the right/left circular time was 1.0 ± 0.08 in the sham rats and 0.62 ± 0.15 in the SNL rats at 4 weeks post-operation. Conclusions We revealed new quantitative parameters in an SNL rat model that are directly relevant to the neurological symptoms in patients with neuropathic pain, in whom the von Frey and thermal withdrawal tests are not used at all clinically. This new 3D analysis system can contribute to the analysis of pain intensity of SNL rats in detail similar to human patients’ reactions following neuropathic pain.


2018 ◽  
Vol 18 (1) ◽  
Author(s):  
Seon-Hee Oh ◽  
Myung Ha Yoon ◽  
Kyung Joon Lim ◽  
Byung Sik Yu ◽  
In Gook Jee ◽  
...  

2020 ◽  
Author(s):  
Chao Xu ◽  
HuiFang Li ◽  
YunPeng Zhang ◽  
TianYu Liu ◽  
Yi Feng

Abstract Background: Neuropathic pain can cause significant physical and economic burden to people, and there are no effective long-term treatment methods for this condition. We conducted a bioinformatics analysis of microarray data to identify related mechanisms to determine strategies for more effective treatments of neuropathic pain.Methods: GSE24982 and GSE63442 microarray datasets were extracted from the Gene Expression Omnibus (GEO) database to analyze transcriptome differences of neuropathic pain in the dorsal root ganglions caused by spinal nerve ligation. We filtered the differentially expressed genes (DEGs) in the two datasets and Webgestalt was applied to conduct GeneOntology (GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of the shared DEGs. String Database and Cytoscape software were used to construct the Protein-Protein Interaction (PPI) network to determine the hub genes, which were subsequently verified in the GSE30691 dataset. Finally, miRDB and miRWalk Databases were used to predict potential miRNA of the selected DEGs.Results: A total of 182 overlapped DEGs were found between GSE24982 and GSE63442 datasets. The GO functional analysis and KEGG enrichment analysis showed that the selected DEGs were mainly enriched in infection, transmembrane transport of ion channels, and synaptic transmission. Combining the results of PPI analysis and the verification of the GSE30691 dataset, we identified seven hub genes related to neuropathic pain (Atf3, Aif1, Ctss, Gfap, Scg2, Jun, and Vgf). Predicted miRNA targeting each selected hub genes were identified.Conclusion: Seven hub genes related to the pathogenesis of neuropathic pain and potential targeting miRNA were identified, expanding understanding of the mechanism of neuropathic pain and facilitating treatment development.


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