Fig. 2: Lymphocyte infiltration in the brain parenchyma at 2 weeks after AAV9 injection.

A Representative images of CD3⁺, CD4⁺, and CD8⁺ immunohistochemistry of the midbrain of animals receiving the AAV9-Control and AAV9-Syn. The frames indicate different sites of lymphocyte entry into the brain: through the lateral ventricle (frame 1), the choroid plexus (frame 2), blood vessels (frame 3), and the interpeduncular fossa (frame 4). B Quantification of the number of infiltrated CD3⁺, CD4⁺, and CD8⁺ T cells per midbrain section in control and αSyn groups. C BBB permeability was analyzed by the administration of Evans Blue 3 h before sacrifice. The Evans Blue signal was not detected in the midbrain and the striatum. Liver was used as a positive control. Data are the mean ± 95% CI from 3 to 4 animals/group. Statistical analysis: B Mann–Whitney test. *p < 0.05. Magnification bar: 1 mm in the first column of images and 10 µm for the remaining columns (frames 1–4).