Articles: neuralgia.
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T-type Ca2+ channels play a dual role in modulating the excitability of dorsal root ganglia neurons.
A subgroup of low-threshold dorsal root ganglia (DRG) neurons discharge action potentials (APs) with an afterdepolarizing potential (ADP). The ADP is formed by T-type Ca2+ currents. It is known that T-type Ca2+ currents contribute to neuropathic pain. ⋯ After injury, the proportion of DRG neurons with large T-type Ca2+ currents increased in parallel with the increase in the incidence of large-amplitude-ADP firing. And in addition to Cav3.2, Cav3.3 channels are also likely to contribute to low-threshold firing. The data revealed that T-type Ca2+ channels may play a dual role in modulating the injured neurons' high excitability through a cooperative process with Na+ channels, thereby contributing to neuropathic pain.
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Ginsenoside Rh2 is one of the major bioactive ginsenosides in Panax ginseng. Although Rh2 is known to enhance immune cells activity for treatment of cancer, its anti-inflammatory and neuroprotective effects have yet to be determined. In this study, we investigated the effects of Rh2 on spared nerve injury (SNI)-induced neuropathic pain and elucidated the potential mechanisms. ⋯ Rh2 treatment blocked the mitogen-activated protein kinase (MAPK) signaling pathway by inhibiting of phosphorylated extracellular signal-regulated kinase expression. Finally, intrathecal injection of TLR8 agonist VTX-2337 reversed the analgesic effect of Rh2. These results indicated that Rh2 relieved SNI-induced neuropathic pain via inhibiting the miRNA-21-TLR8-MAPK signaling pathway, thus providing a potential application of Rh2 in pain therapy.
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Systemic administration of morphine increases serotonin (5-HT) in the spinal dorsal horn (SDH), which attenuates the analgesic effects of morphine on neuropathic pain through spinal 5-HT3 receptors. We hypothesized that dysfunction of the descending serotonergic system, including the periaqueductal gray (PAG), contributes to attenuate the efficacy of morphine on neuropathic pain through spinal 5-HT3 receptors and GABA neurons. Morphine (100 ng) injected into the PAG produced analgesic effects in normal rats, but not in spinal nerve ligation (SNL) rats. ⋯ Functional changes in GABAA receptors from inhibitory to facilitatory through the activation of TrkB receptors may contribute to the attenuated efficacy of morphine against neuropathic pain. PERSPECTIVE: Although morphine provides strong analgesia against acute pain, it has limited efficacy against neuropathic pain. This article demonstrates that functional changes in GABAA receptors in the spinal dorsal horn after nerve injury might strongly contribute to the attenuation of opioid-induced analgesia for neuropathic pain.
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Neuropathic pain (NP) is the cardinal symptom of neural injury, and its underlying molecular mechanism needs further investigation. Complements, especially complement 3 (C3), are involved in the pathophysiology of many neurological disorders, while the specific role of C3 in NP is still obscure. ⋯ Intrathecal injection of C3 antibody and C3aR antagonist alleviated NP in CCI model together with reduced M1 polarization of microglia. Our finding suggested that blockade of the C3/C3aR pathway might be a novel strategy for NP.
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J Coll Physicians Surg Pak · Apr 2022
Dyna-CT-based Image Fusion Technique Real-time-assisted Percutaneous Micro-balloon Compression in the Treatment of Trigeminal Neuralgia.
To investigate the efficacy and safety of percutaneous micro-balloon compression (PBC) assisted by Dyna-CT-based image fusion technique in the treatment of trigeminal neuralgia (TN). This study is the retrospective analysis of the efficacy and safety of 18 patients with TN treated by PBC assisted with Dyna-CT-based image fusion technique from May 2020 to May 2021. The puncture route from the skin to the foramen ovale（FO）was reconstructed after Dyna-CT scanning; and the puncture direction was adjusted according to the virtual puncture route until the puncture was completed. ⋯ Importantly, pain was relieved in all patients, and no puncture-related complications occurred. Dyna-CT-based image fusion real-time-assisted PBC for the treatment of TN is safe and effective, making the operation easier and faster, greatly improving the success rate of the puncture, and reducing the risk of operation-related complications. Key Words: Dyna-CT, Percutaneous micro-balloon compression, Trigeminal neuralgia.