Fig. 5

Lipid deposition in Gde2 null neurons. a–d Sudan Black B darkly stains lipid deposits in motor neurons of the aged Gde2 KO (arrows). Scale bar = 7 μm. n = 3. e–h Lipofuscin (arrows) is visualized as autofluorescent granules using ultraviolet excitation (405 nm) and a long pass emission (LP 505) filter. Scale bar = 10 μm, n = 3. i Quantification of elevated lipofuscin granules at 6 weeks *p = 0.028 and 19 months *p < 0.001, Student’s t test, n = 3. Graph represents mean ± SEM. j Lipofuscin granules have an ultraviolet excitation maxima centered at 390 nm, and a broad emission curve peaking at 530 nm. k, l, m, n, o, p Lipofuscin association with lysosomes labeled by Lamp2 or CathepsinD. Scale bar = 4.25 μm. k’, l’, m’, n’, o’, p’ Magnification of boxed regions in panels k-p. Lipofuscin is fully or partially colocalized with (filled arrows), surrounded by (arrowheads), or devoid of (open arrow) lysosomal signal. Scale bar = 1.5 μm. n = 4