Euthanasia and Tissue Processing
Animals were euthanised 20 weeks after AAV surgery via transcardial perfusion fixation under terminal pentobarbital anaesthesia (50 mg/kg). Brains were post-fixed in 4% paraformaldehyde for 24 h before being cryoprotected in a 30% sucrose solution with 0.1% sodium azide. Using a freezing sledge microtome (Bright, Cambridgeshire, UK), 30μm serial coronal sections were collected in a series of 6.