FIGURE 6

Mature human astrocytes contact developing zebrafish brain vessels. (A–E) Immunocytochemistry of GFP-expressing human astrocytes (green), with DAPI counterstained nuclei (blue) (A), the common marker GFAP (B), and mature markers ALDH1L1 (C), Kir4.1 (D), and GLT-1 (E) (red). Scale bar = 30 μm. (F) 48 h post-implantation, human astrocytes (green) reach out to the surrounding brain vasculature (red) of a 6 dpf Tg(kdrl:mCherry) zebrafish larvae. (G) Green channel highlighting the astrocyte’s morphology. (H) A zoomed in view from the white dotted box in panel (F) showing the astrocyte reaching out to a vessel. n = 5 animals. Scale bar = 10 μm. (I,J) Quantification of human glia-zebrafish vessel interactions. While there was a decrease in human glia present in the brain from 24 to 48 h post-intracranial injection (I), the amount of glial-vessel contacts did not subsequently decrease (J). n = 4 animals in (I) and n = 3–7 animals in (J). A paired, two-tailed t-test was performed (*p < 0.05) in (I) and an unpaired, two-tailed t-test was performed in (J).