Biology subjects

Moalem-Taylor, G.

Publications and source records attributed to Moalem-Taylor, G..

3 recordsLinked to original sources

bioRxiv2023

Peripheral direct current for suppression of physiologically evoked nociceptive responses at the spinal cord

Electrical neuromodulation is an established non-pharmacological treatment for chronic pain. However, existing devices using pulsatile stimulation are not suitable for all types of chronic pain. Direct current stimulation is a recently developed technology which shows better selectivity for small-diameter fibres. We investigated if this selectivity could be applied to preferentially suppress nociceptive signalling. We applied direct current to the sciatic nerve of rats and compared its effects on spinal activity produced by physiological (non-electrical) stimuli delivered to the foot. Tests were performed across models of neuropathic and inflammatory pain to further clarify potential clinical applications. We found that direct current could effectively suppress activity relating to painful stimuli in both pain models tested. These findings strongly support the use of direct current neuromodulation for chronic pain relief, and suggest that it may be effective at treating a broader range of aberrant pain conditions than existing devices.

neuroscience↗

bioRxiv2021

Sex-specific transcriptome of spinal microglia in neuropathic pain due to peripheral nerve injury

Recent studies have suggested a sexually dimorphic role of microglia in the maintenance of neuropathic pain in rodents. Here, we utilized RNA sequencing analysis and in vitro primary cultures of microglia to characterize the sex differences in microglia in pain-related regions in nerve injury and chemotherapy-induced peripheral neuropathy mouse models. Whilst mechanical allodynia and behavioral changes were observed in all models, transcriptomic analysis revealed a substantial change in microglial gene expression only within the ipsilateral lumbar spinal cord 7-days after nerve injury. Both sexes upregulated genes associated with inflammation, phagosome, and lysosome activation, though males revealed a prominent global transcriptional shift not observed in female mice, reflecting acute activation. Further, in vitro studies revealed that only male microglia from nerve-injured mice developed a reactive phenotype with increased phagocytotic activity. This study indicates distinct sex differences in spinal microglia and suggests they contribute to the sex-specific pain processing following nerve injury.

neuroscience↗

bioRxiv2020

Red-light (670 nm) therapy reduces mechanical sensitivity and neuronal cell death, and alters glial responses following spinal cord injury in rats

Individuals with spinal cord injury (SCI) often develop debilitating neuropathic pain, which may be driven by neuronal damage and neuroinflammation. We have previously demonstrated that treatment using 670 nm (red) light irradiation alters microglia/macrophage responses and alleviates mechanical hypersensitivity at 7-days post-injury. Here, we investigated the effect of red-light on the development of mechanical hypersensitivity, neuronal markers, and glial response in the subacute stage (days 1-7) following SCI. Wistar rats were subjected to a mild T10 hemi-contusion SCI or sham surgery followed by daily red-light treatment (30 min/day; 670 nm LED; 35mW/cm2) or sham treatment. Mechanical sensitivity of the rat dorsum was assessed from 1-day post-injury and repeated every second day. Spinal cords were collected at 1, 3, 5 and 7-days post-injury for analysis of myelination, neurofilament protein NF200 expression, neuronal cell death, reactive astrocytes (GFAP+ cells), interleukin1{beta} (IL1{beta}) expression, and inducible nitric oxide synthase (iNOS) production in IBA1+ microglia/macrophages. Red-light treatment significantly reduced the cumulative mechanical sensitivity and the hypersensitivity incidence following SCI. This effect was accompanied by significantly reduced neuronal cell death, reduced astrocyte activation and reduced iNOS expression in IBA1+ cells at the level of the injury. However, myelin and NF200 immunoreactivity and IL1{beta} expression in GFAP+ and IBA1+ cells were not altered by red-light treatment. Thus, red-light therapy may represent a useful non-pharmacological approach for treating pain during the subacute period after SCI by decreasing neuronal loss and modulating the inflammatory glial response.

neuroscience↗