Platelets penetrate the blood-brain barrier (BBB) and accumulate in the lipid rafts-rich areas in the model of neuroinflammation.

<p>(<b>A–C</b>) The platelets isolated from the CNS of healthy mice or mice with EAE were analyzed by flow cytometry. The platelet-rich supernatants were prepared from the CNS homogenates, the platelets were stained for CD41 and CD61 (<b>A</b>) The percentages of CD41⁺CD61⁺ platelets are depicted in the upper right quadrants of the contour plots. (<b>B</b>) The increase of platelet numbers in the brain and spinal cord in the early stages of EAE (Mean ± S.E, five animals per group; **, p<0.01; ***, p<0.001; ****, p<0.0001; when compared to the unmanipulated mice). (<b>C</b>) The immunofluorescent analysis of the platelet localization within the CNS of WT B6 (<b>C</b>) or the Thy1-YFP reporter mice (<b>D</b>) with EAE on day 6. The CNS sections were double stained with CTB (green) and anti-CD41 mAbs (red) in (c, left panel) or single stained with anti-CD41 (red) in (c, right panel). The CD41⁺ platelets are indicated by the arrows. (<b>D</b>) The schematic model of platelets topographic disposition in the perivascular space and their interaction with lipid rafts on astrocytes and neurons as a result of the increased CNS blood vessel permeability. (<b>E–F</b>) The model of the BBB with a “perivascular space” between the monolayer of brain endothelial cells in the top chamber and the astroglial cells in the bottom chamber of the Transwell system (<b>E</b>). The platelets isolated from the ACTB-GFP transgenic mice were added to the top chamber together with MOG/CFA and/or PTx. The percentage of the transmigrated GFP⁺ platelets is shown in (<b>F</b>). The combined bright field (astroglial cells, grey) and fluorescent images (GFP⁺ platelets, green) of the bottom chambers under specified conditions are shown in (<b>G</b>).