Retinal morphology of Leiosauridae lizards: analysis of the density and distribution of cells in the ganglion cell layer of Enyalius perditus and Enyalius iheringii

• Grant number: 25/02161-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: June 01, 2025
• End date: April 30, 2027
• Field of knowledge: Humanities - Psychology - Physiological Psychology
• Principal Investigator: Dora Selma Fix Ventura
• Grantee: Natália Ferreira Torello Viera
• Host Institution: Instituto de Psicologia (IP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 22/00191-0 - Mechanisms, genetics and performance of the visual system: clinical research in humans and animal experiments, AP.TEM

Abstract

The visual system has adaptations to the ecology and natural history of animals. The lizard group has a great diversity of species, with elaborate color vision and high visual acuity. However, few studies have addressed the variability of their visual adaptations. This project aims to investigate morphological aspects of the retinas of Enyalius iheringii and Enylius perditus, diurnal species with variations in habitat use between males and females and between different populations. The preferential use of habitat, arboreal or terrestrial, may be associated with different specializations of the retinas. Regions of greater cell density in the retinas point to particular areas of greater importance in the visual field. Ganglion cells are the last neurons in the retina that receive information initially processed in the outer and inner retina and transmit it to the brain. The density of ganglion cells is, therefore, a limiting factor for the spatial resolution capacity of the eye. Thus, the peak density of ganglion cell, together with anatomical data on the focal distance of the eye, can be used to estimate the limits of visual acuity. This project will compare the ganglion cell density and distribution, as well as the estimated visual acuity based on anatomical data from males and females of different populations of E. iheringii and E. perditus. The results will provide unprecedented information on the adaptive mechanisms of lizard vision.