Brain sections from mouse co-injected with Alexa 647-labelled BSA and GFP-Etx-I51C/A114C or GFP-Etx-V56C/A118C.

<p>Mice were i.v. injected with GFP-Etx-I51C/A114C (A–B) or GFP-Etx-V56C/A118C (C–D) in combination with Alexa 647-labelled BSA. Brains were processed for cryostat sectioning and examined under a confocal microscope. Green fluorescence corresponds to GFP-Etx-I51C/A114C (B) or GFP-Etx-V56C/A118C (D) and blue fluorescence corresponds to BSA (A–D). Red fluorescence corresponds to GFAP labeling (astrocytic processes and perivascular end-feet, A–D). Notice that in GFP-Etx-V56C/A118C-injected mice, both BSA and the GFP-Etx mutant remained confined in the blood vessel's lumen surrounded by the astrocyte's perivascular end-feet (C and D), while in GFP-Etx-I51C/A114C-injected mice, BSA remained in the lumen but the GFP-Etx mutant leaked out of the vessel, beyond astrocytic processes (A and B, arrows). Scale bars correspond to 20 µm (A and B) and 16 µm (C and D).