Neuroscience
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Brachial plexus injury (BPI) often involves the complete or partial avulsion of one or more of the cervical nerve roots, which leads to permanent paralysis of the innervated muscles. Reimplantation surgery has been attempted as a clinical treatment for brachial plexus root avulsion but has failed to achieve complete functional recovery. Lithium is a mood stabilizer drug that is used to treat bipolar disorder; however, its effects on spinal cord or peripheral nerve injuries have also been reported. ⋯ An analysis of myelin-associated genes showed that the effects of lithium started during the early phase of remyelination and persisted through the late stage of the process. Efficient remyelination of the regenerated axons in the lithium-treated rats led to an earlier functional recovery. Therefore, we demonstrated that lithium might be a potential clinical treatment for BPI in combination with reimplantation surgery.
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Thrombolysis with recombinant tissue plasminogen activator (rtPA) is the most effective drug treatment for acute ischemic stroke within 4.5h after symptom onset. However, the use of rtPA may increase the risk of hemorrhagic transformation (HT), particularly when it is administered after the first 4.5h. However, no effective treatments are available to reduce the HT risk. ⋯ Additionally, rtPA administration upregulated p-Cx43 expression in hypoxia/reoxygenation (H/R)-exposed brain endothelial cells. These effects were suppressed by the phosphatidylinositol 3'-kinase (PI3K) inhibitor LY294002 and the extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor U0126. We suggest that rtPA-associated hemorrhage due to an alteration in the integrity of the BBB is highly associated with an increase in p-Cx43 resulting from the activation of the PI3K and ERK pathways.
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Inherited retinal degeneration such as retinitis pigmentosa (RP) is associated with photoreceptor loss and concomitant morphological and functional changes in the inner retina. It is not known whether these changes are associated with changes in the density and distribution of synaptic inputs to retinal ganglion cells (RGCs). We quantified changes in ganglion cell density in rd1 and age-matched C57BL/6J-(wildtype, WT) mice using the immunocytochemical marker, RBPMS. ⋯ Distribution patterns of both synaptic markers across the dendritic trees of RGCs were unchanged. The change in synaptic inputs to RGCs was associated with a reduction in the number of immunolabeled rod bipolar and ON cone bipolar cells. These results suggest that functional changes reported in ganglion cells during retinal degeneration could be attributed to loss of synaptic inputs.