The retinal functions of TGR rats were further reduced at 3 months after birth, whereas ERGs in 3-month SD rats were unaltered. In this study, we identified a novel rat model with a defect in a cilia gene that mimics specific phenotypic changes which are likewise observed in diabetic retinopathy. In contrast to diabetic retinopathy,SU5416 however, this model exhibits primary neuronal degeneration followed by vasoregression with a loss of capillary endothelial cells and pericytes during the second phase. Subse-quent progressive impairment of retinal functions and concomi-tant glia activation and induction of neurotrophins in the retina of transgenic rat occur, which are at least in part similar to the pathologic evolution in diabetic retinopathy. While the expression of FGF2 and CNTF likely reflects a response to photoreceptor damage, NGF regulation may have a close link to retinal vasoregression. An important finding in this study is the temporal attribution of neuronal damage with vasoregression. In TGR rats, photoreceptor cell death via apoptosis with a loss of cells in the inner nuclear layer develops during the first month prior to vasoregression which follows during the second month. Despite similarities of the neuronal changes in TGR rat with several animal models such as the rd/rd, rds mouse and Royal College of Surgeons rat, and reported vascular alterations, specific differences exist regarding the onset and developmental dynamics of the photore-ceptor death. For example,Temozolomide in the rd/rd mouse, rod cell death starts at the second week and is completed by the third week. In this model, the vasculature starts to regress while still developing. Vascular changes are unknown in the rds mouse model with early onset at 2 weeks and slow progression of retinal degeneration up to 12 months. Moreover, late vascular changes due to the progressive loss of photoreceptors are reported from RCS rats, but neither the temporal and spatial allocation nor an exact quantitation of vascular damage has been provided. We observed both exponential vasoregression and pericyte loss in the TGR model.