At least 4 weeks after viral injection mice were perfused transcardially with 4% paraformaldehyde. Brains were extracted, sliced and processed with an anti-ChAT polyclonal antibody and a fluorescein-conjugated secondary antibody. Sections were then mounted and visualized by epifluorescence with a Leica DM LB microscope to identify ChAT-labeled and eYFP-positive neurons.
