Figure 4 : CSF1R inhibition eliminates IBA-1+ microglia from the unirradiated and irradiated hippocampus.

From: Elimination of microglia improves cognitive function following cranial irradiation

Figure 4

(A) Immunofluorescence staining and laser scanning confocal microscopy demonstrates that PLX5622 treatment for 6 weeks eliminates ~90% of IBA-1+ microglia from the control (0 Gy + PLX5622) and irradiated (9 Gy + PLX5622) brains. (a1,a2) Representative high-resolution (60×) confocal micrographs from the hippocampal dentate hilus (DH) and granule cell layer (GCL) are shown for the 0 and 9 Gy mice that received control chow. (B) 3D algorithm-based quantification (Autoquant and Imaris) of IBA-1+ microglia show almost complete elimination (90–96%) of microglia in the control and irradiated brains of animals treated with PLX5622 (0 Gy + PLX5622 and 9 Gy + PLX5622) at 2 week and 6 week post-treatments. (C) Gene expression analysis of microglial markers from whole brains derived from a separate cohort of irradiated animals (0 and 9 Gy) received 1 week of PLX5622 treatment at 4 week post-irradiation show 80–90% reduction in mRNA levels after treatment with PLX5622. Data are presented as mean ± SEM (N = 4 mice/group). P values are derived from ANOVA and Bonferroni’s multiple comparisons test. *P < 0.001 compared with 0 Gy group and +P < 0.001 compared with the 9 Gy group. Scale bars: 200 μm (A) and 20 μm (a1,a2).