Why do Cone Photoreceptors Die in Rod-Specific Forms of Retinal Degenerations?

Retinal degenerations such as retinitis pigmentosa (RP) lead to rod death due to apoptotic cell death, initiated by mutations in retinal genes that encode proteins with crucial photoreceptors functions. The mechanism(s) of cone death have remained elusive until this study. Using a combination of animal models of human RP, Affymetrix expression array studies, RT-PCR and immunohistochemical analyses, Punzo et al. determined that cone death is due to nutritional deficiencies, starration, and autophagy driven by the insulin/mTOR pathway. These novel and exciting seights also provide alternative avenues for therapeutic interventions for cone rescue.