Functional Recovery Following Regeneration of rhe Damaged Retina in the Adult Newt, Notophthalmus Viridescens

Abstract

A hallmark of retinal diseases is degeneration of neural cells, leading to subsequent vision loss. For such diseases, replenishment of functional neural cells may be an optimal therapy. Unlike humans, the adult red-spotted newt, Notophthalmus viridescens, possesses the remarkable ability to regenerate a complete retina following its removal or injury. The purpose of this study was to develop a reproducible model of retinal damage and regeneration in the newt to understand the process of retinal regeneration. Intense light, shown in other organisms to be a relevant model of visual cell loss, was tested in the newt and resulted in variable loss of retinal function, correlating with the appearance of apoptotic cells. Due to the variability of damage observed, surgical removal of the retina was used to complement the light-damage model. A novel and non-invasive protocol using full-field electroretinography was developed to assess retinal function in vivo following damage. Measures of retinal function with the electroretinogram protocol successfully showed that photoreceptor function is initially lost and subsequently restored during regeneration. These results enhance our understanding of retinal regeneration in the adult newt and serve as a starting point for further studies aimed at determining the molecular mechanisms involved in the regeneration process.