The TSPO ligand XBD173 reduces the number of alerted amoeboid retinal microglia ex vivo . (A-D) Representative GFP images of the retinal microglia network in explanted mouse retinas treated for 24 hours with vehicle (A), 20 μM XBD173 (B), 1 μg/ml LPS + vehicle (C) and 1 μg/ml LPS + 20 μM XBD173 (D). (E) Quantification of ramified and amoeboid microglial cells in 10 independent image areas of two individual flat mounts (mean ± SEM). **P <0.01 for amoeboid cells in LPS versus control explants; ***P <0.0001, for amoeboid cells in XBD173 + LPS versus LPS-treated explants. GFP, green fluorescent protein; LPS, lipopolysaccharide; TSPO, translocator protein (18 kDa).