Fig. 1

Intravitreal LPS induces rapid activation of inner retinal glial cells. LPS was injected intravitreally and several markers of resident and infiltrating inflammatory cells were monitored over 8 days. A Increased Müller cell and astrocyte reactivity in the inner retina was detected with the marker GFAP in glial fibers (arrows) by day 2. B Staining with the macrophage marker F4-80 (green) indicated a marked increase of infiltrating cells at the vitreo-retinal interface (arrows) in the inner retina by day 2, as well as activated microglia (asterisks). C Iba1 staining for microglial density was generally consistent within the retina across sections (asterisks), but also highlighted the appearance of vitreo-retinal macrophages (arrows). D GR-1 positive neutrophils infiltrated into the vitreous by 24 h after LPS (d1) where they accumulated at the inner retinal surface (green; arrows). However, GR-1 positive cells were never substantially observed within the retina, and had largely disappeared by 2 days post LPS injection (d2–d8). E Representative higher magnification images of the markers used (scale bars represent 20 µm). F Representative retinal Iba-1 stained images of ramified or amoeboid microglial morphology in the LPS-treated group (scale bar represents 20 µm). G Quantification of total inner-retina Iba1-positive cells on day 2 shows no significant change in macrophage/microglia numbers in the LPS group compared to vehicle (bars represent SE). (GCL; ganglion cell layer, INL; inner nuclear layer, scale bars of A–D represent 100 µm)