Article
The glymphatic drainage system is impaired in the acute phase of experimental subarachnoid haemorrhage
Das glymphatische Drainagesystem ist in der akuten Phase der experimentellen Subarachnoidalblutungbeeinträchtigt
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Published: | June 26, 2020 |
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Objective: The glymphatic system was discovered as a supposed perivascular pathway clearing the brain from solutes by convective transportation along the vasculature. The impact of acute subarachnoid hemorrhage (SAH) on this important perivascular transport system is incompletely understood. Therefore we established a model for assessment of the glymphatic system in SAH.
Methods: The cisterna magna injection model for SAH in a rat was used to assess glymphatic drainage properties. Application of the fluorescence marker Alexa 594 was followed by autologous blood injection. Brains were then harvested at three different time points (15 minutes, 1 hour, 4 hours), followed by cryofixation and separation into 10 µm brainslices. Visualization was achieved via anti-GFAP (astrocytes) and anti-von Willebrand factor (anti-vWF, endothel) stainings.
Results: Subarachnoidal injection of Alexa 594 resulted in fluorescent signals between the anti-GFAP- (astrocytic endfeet) and anti-vWF- (endothelial layer) positive signals. Histogram analysis of different brain areas in SAH animals compared with sham operated animals showed a significant compromise of the newly identified transportation process.
Conclusion: In the acute phase after subarachnoid hemorrhage the glymphatic drainage system is severely compromised. These immediate alterations may play an imminent role in both early brain injury and delayed complications after SAH, warranting further analysis. Our animal model offers the possibility to analyze the impact of increased intracranial pressure and blood components on the glymphatic drainage.