Fig. 10

Characterisation of microglial changes in transverse retinal sections of Rd1 mice. a–e Representative images of Iba1 immunolabeling in C57BL/6 wild-type (WT) mice and in Rd1 mice from postnatal day (P) 14 to P75. In WT retinas, Iba-positive microglia are restricted to the nerve fiber, inner plexiform, and outer plexiform layers and had ramified cell processes (a, arrow). In Rd1 mice, Iba1-positive microglia within the inner retina retain their ramified appearance (b, arrow), but there is an accumulation of microglia with an amoeboid appearance (arrowhead) in the outer nuclear layer (ONL) at P14, which coincides with photoreceptor degeneration (b). By P21, the density of Iba1 microglia in the ONL has decreased substantially (c, arrowhead) and continues to decrease at later time points (d, e, arrowhead). f Quantification of the number of Iba1-positive cells in the ONL over time. Scale bar = 50 μm. GCL ganglion cell layer, INL inner nuclear layer