Figure 4. Partial prevention of vigabatrin-retinal toxicity in mice by taurine suppementation.

(A–F) Retinal sections showing that VGB-elicited retinal lesions are less extensive in a mouse with a taurine supplementation (C, F, VGB + taurine) than without (B, E, VGB), but still greater than in a control animal (A, D). These sections were immunolabelled with antibodies directed against Goα (red in A–C) and GFAP (green in A–C) and stained with a peanut lectin (PNA, red in D–F) and DAPI (blue in A–F). Photoreceptor nuclei displaced above the outer nuclear layer (ONL) were only observed in the VGB-treated mice (B), not in control animals (A) or VGB-treated mice receiving taurine supplementation. GFAP-positive processes extending vertically throughout the retina were observed in the VGB-treated animals (B), and increased GFAP staining was also observed in VGB-treated mice with taurine supplementation (C), compared to control animals (A). Similarly, there were fewer PNA-positive inner/outer segments of photoreceptors in VGB-treated mice (E) than in either control animals (D) or VGB-treated mice with taurine supplementation. Quantification of photopic ERG amplitude (G), length of retinal areas with displaced photoreceptor (PR) nuclei (H), density of cone inner/outer segments (I) and areas with bipolar cell sprouting into the ONL (J) in control mice (s.e.m., n=5), in VGB-treated animals with or without taurine supplementation (VGB, s.e.m., n= 7; VGB + taurine, s.e.m., n= 7). The scale bar represents 50µm (IPL: inner plexiform layer).