CCL2 and retinal degeneration: In order to verify the hypothesis, we performed three experiments using rd10 mice: (1) in vivo FAF imaging during the retinal degeneration, (2) histopathological examination of retinal specimen at the same time points with in vivo FAF imaging to investigate the related pathological event such as apoptosis of the photoreceptors and infiltration of microglia, and (3) analyses of the expression levels and the localization of microglial chemotactic factors, fractalkine and MCP-1.