Neuroscience
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Intracellular accumulation of alpha-synuclein (α-syn) is a key pathological process evident in Lewy body dementias (LBDs), including Parkinson's disease dementia (PDD) and dementia with Lewy bodies (DLB). LBD results in marked cognitive impairments and changes in cortical networks. To assess the impact of abnormal α-syn expression on cortical network oscillations relevant to cognitive function, we studied changes in fast beta/gamma network oscillations in the hippocampus in a mouse line that over-expresses human mutant α-syn (A30P). ⋯ A deficit in COX IV expression was confirmed by immunohistochemistry. Overall, our data demonstrate an age-dependent impairment in mitochondrial function and gamma frequency activity associated with the abnormal expression of α-syn. These findings provide mechanistic insights into the consequences of over-expression of α-syn which might contribute to cognitive decline.
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Post-stroke hyperglycemia during early reperfusion increases blood-brain barrier (BBB) permeability and subsequently aggravates brain injury and clinical prognosis. The decreased level of tight junction proteins (TJPs) has been reported but the underlying mechanism remains largely elusive. Herein we designed to investigate the detailed molecular events in brain microvascular endothelial cells (BMECs) ex and in vivo. ⋯ Therefore, high-glucose exposure in the early reperfusion causes the BBB disruption, with MMP-2/9-mediated extracellular degradation, caveolin-1-mediated intracellular translocation and autophagy-lysosome-mediated degradation of ZO-1 protein all together involved in the process. The role of MMP-2/-9 and autophagy in the modulation of paracellular permeability was confirmed by pharmacological inhibition. Therefore, our findings may provide new insights into targeting ZO-1 regulation for the purpose of significantly improving the clinical prognosis of ischemic stroke.