Glial scars are permeable to the neurotoxic environment of chronic stroke infarcts

Another neuronal death cause your doctor should be working with researchers on. Or is your doctor going to do NOT ONE DAMN THING like usual? And your stroke president and board of directors are complicit in that incompetency.
https://www.sciencedirect.com/science/article/pii/S096999611830007X

Author links open overlay panelJacob C.Zbesko^aThuy-Vi V.Nguyen^abTaoYang^eJennifer BeischelFrye^aOmarHussain^aMeganHayes^aAmandaChung^aW. AnthonyDay^dKristinaStepanovic^aMajKrumberger^aJustineMona^aFrank M.Longo^eKristian P.Doyle^abc

https://doi.org/10.1016/j.nbd.2018.01.007Get rights and content

Open Access funded by National Institutes of Health

Under a Creative Commons license

open access

Highlights

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Liquefactive necrosis lasts for weeks following stroke.

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The extracellular fluid in areas of liquefactive necrosis is neurotoxic.

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Glial scars are permeable to the extracellular fluid present in areas of liquefactive necrosis.

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There is progressive neurodegeneration around areas of liquefactive necrosis after stroke.

Abstract

Following stroke, the damaged tissue undergoes liquefactive necrosis, a stage of infarct resolution that lasts for months although the exact length of time is currently unknown. One method of repair involves reactive astrocytes and microglia forming a glial scar to compartmentalize the area of liquefactive necrosis from the rest of the brain. The formation of the glial scar is a critical component of the healing response to stroke, as well as other central nervous system (CNS) injuries. The goal of this study was to evaluate the toxicity of the extracellular fluid present in areas of liquefactive necrosis and determine how effectively it is segregated from the remainder of the brain. To accomplish this goal, we used a mouse model of stroke in conjunction with an extracellular fluid toxicity assay, fluorescent and electron microscopy, immunostaining, tracer injections into the infarct, and multiplex immunoassays. We confirmed that the extracellular fluid present in areas of liquefactive necrosis following stroke is toxic to primary cortical and hippocampal neurons for at least 7 weeks following stroke, and discovered that although glial scars are robust physical and endocytic barriers, they are nevertheless permeable. We found that molecules present in the area of liquefactive necrosis can leak across the glial scar and are removed by a combination of paravascular clearance and microglial endocytosis in the adjacent tissue. Despite these mechanisms, there is delayed atrophy, cytotoxic edema, and neuron loss in regions adjacent to the infarct for weeks following stroke. These findings suggest that one mechanism of neurodegeneration following stroke is the failure of glial scars to impermeably segregate areas of liquefactive necrosis from surviving brain tissue.