A web‐based archive for topographic maps of retinal cell distribution in vertebrates

Abstract

Clinical and Experimental Optometry, in conjunction with Optometrists Association Australia and Professor Shaun P Collin of the University of Queensland, announce the launch of a web‐based archive of previously published topographic maps of retinal cell distribution in vertebrates. At present, the archive boasts more than 770 different maps of the distribution of retinal neurons (for example, photoreceptors, bipolar cells, amacrine cells, horizontal cells and ganglion cells) in nearly 200 species within all vertebrate classes (Cephalospidomorpha, Actinopterygii, Sarcopterygii, Amphibia, Reptilia, Aves and Mammalia). The distribution of retinal neurons has been studied for more than 100 years and has become a powerful means of predicting the spatial resolving power of the eye and the retinal regions containing specialisations, such as areae centrales, horizontal streaks and foveae, where increased densities of neurons define the way in which a species visually samples its environment. The location of these retinal specialisations thereby identifies the part(s) of the visual field of critical importance for localising food and mates and for predator surveillance. The distribution of sampling elements even reflects the symmetry of a species' ecological habitat. The archive is a unique collection of most of the currently available retinal maps, which also presents relevant information, where known, about eye size, retinal cell density, retinal orientation, cell number, spatial resolving power and the type of specialisation, in addition to basic physical parameters of each species (body size, weight, sex and developmental stage). The archive is accessible at http://www.optometrists.asn.au/ceo/retinalsearch and will be updated regularly. The powerful database is interactive and freely available, providing the opportunity to upload both published and unpublished topographic maps. Following a review process, previously unpublished maps will be ‘published’ and available online worldwide. It is hoped that this comprehensive new resource will provide not only an up‐to‐date method of accessing maps of the distribution of retinal neurons in individual species but also allow broader evolutionary comparisons of the visual capabilities, ecology, development and the type(s) of retinal specialisations found in vertebrates.

Key words:

• amphibians
• area centralis
• birds
• fishes
• fovea
• ganglion cells
• horizontal streak
• mammals
• photoreceptors
• reptiles
• retinal topography

ACKNOWLEDGEMENTS

I thank Optometrists Association Australia for the generous support of this project, in particular Joe Chakman, Professor Barry L Cole, Professor H Barry Collin, Diana Fayle, Maria deSouza and Karen Murray. Many thanks also to Jo Hooper and Tristan Bennett from Datalink Internet Systems, who provided expert technical assistance to me and for developing the website. I extend my sincere gratitude to Sarah Rogers, Nicole Barnes and Maree Knight, who painstakingly sourced the data for the archive; their hard work is much appreciated. Finally, I acknowledge Professor Jack Pettigrew for hatching the idea and to all those visual neuroscientists (past and future) that have or will contribute their topographic maps to this database for the enrichment of others.