Research Paper Volume 8, Issue 10 pp 2488—2508
Dissociation between iron accumulation and ferritin upregulation in the aged substantia nigra: attenuation by dietary restriction
Figure 8. (A) Dietary restriction ameliorates age-related increases in in vivo R2 in the SN. Black asterisks placed above specific age time points indicate differences between Ad libitum (AL) and dietary restricted (DR) mice after post-hoc test (significance levels ** P < 0.01 and *** P < 0.001). Significance level at **** P < 0.0001 for an effect of age when placed at the end of the graph; ### P < 0.001 for an effect of treatment; αα, P < 0.01 for an age-feeding regimen interaction. (B) Age-related reductions in ferritin-immunopositive cell numbers in the SN between 7 and 19 months are ameliorated in DR mice compared to AL mice. [Solid black line indicates the outcome of two-way ANOVA testing; *** P < 0.001 for effect of age; no significant effect of DR or age-feeding regimen interaction. Dotted line indicates post-hoc testing at significance level ** P < 0.01.] Micrographs showing decreased ferritin-positive cells in SN of (C) AL compared to (D) DR mice at 19 months of age. Black arrows point to ferritin-immunopositive cells.