Electron microscopy

Light and electron microscopy analysis were performed as described (Büssow 1978; Uschkureit et al. 2000). Briefly, 2,2,2-tribromoethanol-anesthetized adult tg mice and wt littermates from the line 4717 were perfused with 6% glutaraldehyde via the left cardiac ventricle. The optic nerves were isolated and post fixed in phosphate-buffered osmium tetroxide (OSO4) in sucrose, and embedded using Epon 812. The semi thin sections generated from the embedded optic nerves were stained with toluidine/pyronin and the ultra-thin sections were contrasted with uranyl acetate and lead citrate and examined as described (Büssow, 1978).