Fig. 3

Functional analysis of spinal microglia with aging and obesity. a) Expression of FcγR III/II (CD16/32) on CD11b⁺ microglia in the spinal cords. CD16/32 (red) expression was found in dorsal horns of lumbar spinal cords in aged animals (lean and DIO 17 month-mice), which was colocalized with CD11b⁺ microglia (green). Only few CD16/32⁺/CD11b + microglia was observed in lean 3, 6, and DIO 6 month-mice. b) CD68 expression was closely associated with lipofuscin accumulation in aged microglia. Arrows indicate CD68 staining (blue, left) and lipofuscin pigments (green, right). The increased lipofuscin deposit with aging (lean 17 and DIO 17 month-mice) was closely associated with CD68. CD68 signals in obese and aged mice anatomically matched with intracellular aggregation of lipofuscin