Fig. 9

CSF1R inhibitor-mediated microglial depletion reveals microglial dependent and independent effects of abx on astrocyte phenotypes. (A) Experimental schematic. (B) Representative merged (a, d), GFAP (b, e) and Aβ (c, f) immunosignal images from VHL M (a-c) ABX M (d-f). (C) Quantification of GFAP + astrocyte number/µm². (D) GFAP + astrocyte percent area. (E) Plaque-associated astrocyte number/µm². (F) Plaque-associated astrocyte percent area. (G) Plaque-associated astrocytes/µm² normalized to Aβ plaques/µm² in PLX male and PLX + ABX male APPPS1-21 mice. (H) Representative GFAP, C3, and Aβ merged astrocyte z-stack maximum projections (g, m), IMARIS 3D reconstructions (k, q), and IMARIS filament 3D reconstructions (l, r) for PLX male (g-l), PLX + ABX male (m-r) groups. GFAP (h, n), C3 (i, o), and Aβ (j, p) shown as separate channels from merged images. (I) Quantification and comparison of astrocyte mean process length sum (µm). (J) Astrocyte mean process area sum (µm²). (K) Astrocyte mean process volume sum (µm³). (L) Astrocyte soma area/GFAP area. (M) Astrocyte C3 area/GFAP area. (N) Astrocyte mean number of processes. (O) Astrocyte mean number of process branch points. (P) Astrocyte mean number of process terminal points between PLX male and PLX + ABX male groups. M = male. Data expressed as mean ± standard deviation. PLX M N = 7, PLX + ABX M N = 8. Statistics calculated using two-tailed unpaired student’s t-tests. 4 sections used per animal. * denotes a p-value ≤ 0.05, ** indicates p-value ≤ 0.01, *** indicates p-value ≤ 0.001, and **** indicates a p-value of ≤ 0.0001. Scale bars indicate 50 µm in B and 10 µm in H