Representative Western blot for Pgp, Mrp1 and Actin on Gunn preparations.

<p>Pgp expression was analyzed on microvessels (MVs) preparations (A, upper panel). Mrp1 was quantified in lateral and 4<sup>th</sup> ventricle (LV and 4<sup>th</sup>V) choroid plexuses (B, upper panel). Actin staining (both A and B, lower panel) was used to normalize the amount of samples loaded. For the quantification procedure, see the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0016165#s2" target="_blank">material and methods</a> section.</p>