Neonatal inflammation induces reorganization in dendritic morphology of retinal ganglion cells but not their retinogeniculate projection in mice

The adenosine A2A receptor antagonist KW6002 distinctly regulates retinal ganglion cell morphology during postnatal development and neonatal inflammation

“…We further studied the effect of A 2A R on RGC morphology after neonatal LPS exposure and found that antagonism of A 2A R changed the compositions of the three RGC types, while no composition change was found in normal development or after neonatal inflammation (Supplementary Figure S1) (Gao et al, 2018). Previous studies have reported that the A 2A R antagonist prevents RGC loss in retinal organotypic cultures upon exposure to LPS (Madeira et al, 2015) and in several models of retinal neurodegeneration (Madeira et al, 2016;Boia et al, 2017;Aires et al, 2019a;Aires et al, 2019b).…”

“…However, what exact role of A 2A R plays in retinal development, especially RGC morphogenesis, is still not be fully elucidated. To simplify the framework for analysis of rather heterogenous RGC types in the retina, here we classified the Thy1-positive RGCs from Thy-1 YFPH transgenic mouse strain into three major morphological types (Type I, II and III) as our previous study (Gao et al, 2018). We found that A 2A R antagonist KW6002 produced mainly decreased RGC morphogenesis as evident by the reduced dendritic field area of Type II and III, and the reduced dendrite density of Type I but with the increased dendrite density of Type III (Figure 9).…”

“…Immunohistochemistry experiments were carried out as previously described (Gao et al, 2018). Briefly, after the Thy1-YFPH mice were anesthetized, the eyes were enucleated on P21 and fixed in 4% paraformaldehyde (PFA) for 30 min.…”

“…The fully and strongly stained YFP-positive RGCs (that achieve the standard for the detailed morphological analyses) were randomly selected and reconstructed, while those with faint staining and uncompleted structure were discarded. The morphology of RGCs was reconstructed by using Neurolucida system (MicroBrightField Inc., USA) and a bright-field light microscope (Zeiss, Germany) at a magnification of ×63, as previously described (Gao et al, 2018). A battery of morphological parameters were extracted from 251 fully reconstructed RGCs by the NeuroExplorer (MicroBrightField Inc., USA).…”

“…3D reconstruction of well-stained YFP + cells (n = 120 cells) for detailed morphometric analyses was performed in the retina at P21 (Figure 1B). As described previously, we classified these Thy1-positive RGCs labeled with YFP into three major morphological classes (Type I, II and III), based on the morphological features of the dendritic field and dendrite density (Gao et al, 2018). Type I had a small dendritic field area and high dendrite density, whereas Type III had a large dendritic field area but low dendrite density.…”