Figure 8.

Validation of FUS+MB induced neutrophil recruitment: MRgFUS+MB experiments. To confirm that neutrophils were present in the brain due to FUS+MB treatments and not solely because of the cranial window surgery, MRgFUS+MB treatments, which do not require a cranial window, were administered. Areas of increased BBB permeability are evident from (A) gadolinium leakage in contrast-enhanced T1-weighted MRI (hyperintensity, white) and (B) Evans blue dye leakage in the targeted brain region (blue, emphasized by red outlines). The blue asterisk indicates the sonicated hemisphere, and the orange asterisk indicates the contralateral hemisphere (reference for F). (C-E) Sagittally cut brain sections were stained for neutrophils (MPO, magenta) and blood vessels (CD31 and GLUT1, white), and counterstained with DAPI (cyan). Evans blue leakage is shown by the dotted red shapes. (F) Sonicated hemispheres (18.6 ± 9.5, n = 5) harboured significantly more neutrophils compared to the contralateral hemisphere (7.4 ± 3.5, p = 0.03, n = 5), and to control animals (5.6 ± 2.4, p = 0.01, n = 5). Mean ± SD. Scale bar: 10 µm. GLUT1: glucose transporter 1, MPO: myeloperoxidase. Boxplots show median, and upper and lower quartiles.