NeuroD2 CRISPant tadpoles have a comparatively leaky BBB. a) Dorsal view of stage 47 tadpole head to show the parts of the brain and site of Na fluorescein (NaF) injection into the hindbrain ventricle (red circle and arrow). FB, forebrain; MB, midbrain; HB, hindbrain; SC, spinal cord. b) Examples of NaF dye injected tadpoles at 2 and 20 minutes after injection, visualized with GFP2 channel. Orientation of the tadpole head as in (a). Dotted rectangles show the area outside the brain that was used to calculate MFI. Scale bar in top left applies to all panels. Top, wild type (WT) tadpole treated with 5 mM of seizure-inducing drug PTZ for 2 hours prior to dye injection. Bottom, untreated NeuroD2 CRISPant, sgRNA rnk20. c) Scatter plot showing MFI (dye leakage outside the brain) at 2 and 20 minutes post NaF dye injection for N = 12 tadpoles per group, 2-way ANOVA with Tukey post hoc analysis, ****P < 0.0001. Cas9 indicates tadpoles injected with Cas9 protein, but no sgRNA. d) Summary of tadpole editing in the NeuroD2 CRISPant group, confirmed by Sanger sequencing and TIDE analysis. Raw data are in Supplementary File 1 and Supplementary Fig. 5 in Supplementary File 2.