FIGURE 4

Zebrafish vision declines with ageing, which is accompanied by signs of glial morphological alterations. (a) OKR assay was performed by immobilising the fish in between soft sponges, inside a petri dish containing water, placed in the centre of a rotation chamber. The walls of the rotation chamber had 0.8 mm‐thick black and white stripes and the chamber was maintained at a constant velocity of 12 rpm throughout the experiment. (a’) The number of eye rotations per minute was manually quantified by video observation. Error bars represent the SEM. N = 5–8. (b) MG display signs of altered morphology at old ages, as evidenced by Gfap staining. The central retina immunolabelled with Gfap (in green), in WT, young (5 months) and old adults (>30 months). Yellow arrows highlight an example of aligned versus misaligned MG projections. (b’) Quantifications of the percentage of fish presenting disorganised MG processes in the IPL (detailed view‐inset). N = 6. (c–e) MG in the old retina show altered morphology and altered expression of stress proteins. The central retina immunolabelled with (c) Vimentin, (d) Cralbp, and (e) GS showing disorganised MG in old adults (>30 months) compared with young adults (5 months). N = 6. Scale bars: 20 μm