Fig. 4
Microglia-selective deletion of Csf1r results in significant loss of microglia in the developing cerebellum. a–l Immunostaining for CX3CR1 (red), Iba1 (green), and DAPI (blue) in control mice (a–i) and Csf1r-cKO mice (j–l) at P7 (left), P14 (middle), and P21 (right). Images are maximum z-projections of slices with thicknesses of 50 μm taken from lobules VI–V in the vermis. In Csf1r-cKO mice, CX3CR1-positive cells were almost absent at P7 (j), and sparse at P14 (k) and P21 (l). m, n Enlargements of the CX3CR1-positive cells surrounded by dashed squares in h and k, respectively. o Summary box plots showing postnatal changes of the density of CX3CR1-positive cells in the IGL and ML in control (blue) and Csf1r-cKO (red) mice. The density of CX3CR1-positive microglia was significantly lower in Csf1r-cKO mice than control mice at all postnatal days that we examined (p < 0.001 at P7, p < 0.001 at P11, p = 4.21 × 10−12 at P14, p = 2.01 × 10−10 at P17, p = 1.26 × 10−7 at P21). ***p < 0.001. The density of microglia was measured in 11–19 images containing the IGL and the ML in lobules IV–V of the cerebellar vermis (256 μm × 256 μm) from three to five mice. Scale bars, 30 μm (a–l) and 10 μm (m, n)
