Fig. 3.

Advanced age results in accumulation of clasmatodendrosis in the stratum radiatum of the dorsal hippocampus. S100β labeling reveals a significant accumulation of degenerative astrocytes. a Low power magnification of dorsal hippocampus shows the distribution of clasmatodendrosis localized within the stratum radiatum of the CA1 region of the hippocampus (orange arrows). b High power magnification shows the distinctive enlarged soma and vacuolization of processes distinctive to clasmatodendrosis for a representative cluster of astrocytes. c Imaris surface render of a confocal z-stack of GFAP (blue), S100β (green), and Vimentin (Red) demonstrates an astrocyte with clasmatodendrosis (left) showing the co-localization of S100β⁺Vimentin⁺ beads along GFAP⁺ processes, and a reactive astrocye with non-degenerative morphology adjacent to it (right). d There is a significant accumulation of clasmatodendrosis in the aged brain, which did show some temporal response to TBI at 3 days post-injury; however by 7 days, levels return to approximate those in the uninjured condition. n = 4–5/group. Data were analyzed using two-way ANOVA with Sidak-Holm post hoc correction examining pairwise interactions for each time interval. ANOVA revealed a significant main effect due to age (F (1, 28) = 64.41, P < 0.0001); however, neither interval nor their interaction were significantly different. **P < 0.01 for pairwise comparisons of sham, 1-day, and 7-day interval between young and aged mice. n = 4–5/group. Data are presented as mean ± SEM. Young, gray bars; Aged, blue bars