Abstract
Light-induced lesions are a powerful tool to study the amazing ability of photoreceptors to regenerate in the adult zebrafish retina. However, the specificity of the lesion towards photoreceptors or regional differences within the retina are still incompletely understood. We therefore characterized the process of degeneration and regeneration in an established paradigm, using intense white light from a fluorescence lamp on swimming fish (diffuse light lesion). We also designed a new light lesion paradigm where light is focused through a microscope onto the retina of an immobilized fish (focused light lesion). Focused light lesion has the advantage of creating a locally restricted area of damage, with the additional benefit of an untreated control eye in the same animal. In both paradigms, cell death is observed as an immediate early response, and proliferation is initiated around 2 days post lesion (dpl), peaking at 3 dpl. We furthermore find that two photoreceptor subtypes (UV and blue sensitive cones) are more susceptible towards intense white light than red/green double cones and rods. We also observed specific differences within light lesioned areas with respect to the process of photoreceptor degeneration: UV cone debris is removed later than any other type of photoreceptor in light lesions. Unspecific damage to retinal neurons occurs at the center of a focused light lesion territory, but not in the diffuse light lesion areas. We simulated the fish eye optical properties using software simulation, and show that the optical properties may explain the light lesion patterns that we observe. Furthermore, as a new tool to study retinal degeneration and regeneration in individual fish in vivo, we use spectral domain optical coherence tomography. Collectively, the light lesion and imaging assays described here represent powerful tools for studying degeneration and regeneration processes in the adult zebrafish retina.
Highlights
The teleost retina is closely related to the human retina, both in respect to its cell types and their laminated arrangement
We characterized two different light lesion paradigms using intense light in detail. One of these light lesion paradigms has been established before in normally pigmented fish [4] and compared to low intensity light lesion paradigms in albino fish [18]
The aim of the second, newly established light lesion paradigm was to direct the light onto a defined area of only one of the eyes
Summary
The teleost retina is closely related to the human retina, both in respect to its cell types and their laminated arrangement. One paradigm used long exposures to bright halogen light (,20 000 lux total light intensity) on dark-adapted albino animals, and comprehensive studies of lesion characteristics with respect to regional differences, affected cell types and cell death time course have been performed [10,14]. Characteristic for these light lesions is the extensive cell death of photoreceptors in the central and dorsal, but not in the ventral part of the retina. The second paradigm used short exposure for only 309 to strong UV light from a mercury arc lamp
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call