Electroretinogram in Melanopsin (Opn4) Knockout Mice

• Grant number: 24/05578-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2024
• End date: April 30, 2025
• Field of knowledge: Humanities - Psychology - Physiological Psychology
• Principal Investigator: Dora Selma Fix Ventura
• Grantee: Gabriela Nicolau Gorgueira
• 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

Melanopsin (Opn4) is a photopigment composed of vitamin A and a member of the receptors coupled to the G protein present in the skin, heart and retina of vertebrate animals. Previous literature has demonstrated direct involvement in the synchronization of the circadian rhythm, reflexes of pupil, melatonin suppression and other light regulation activities. More specifically, it works by measuring the intensity of light received, and unlike classic rod and cone opsins, it is much less sensitive to light and has lower spatial resolution, characteristics that are perfectly suited to its main function of signaling changes in light levels in the environment to the brain throughout the day. This project seeks, through the electroretinogram, to analyze the electrophysiological changes in the functioning of retinal cells in knockout mice for the Opn4 gene, using an expansion of the clinical protocol of ISCEV (International Society of Clinical Electrophysiology of Vision - International Society for Clinical Electrophysiology of Vision) (Marmor et al, 2008), previously described by Tsai and colleagues (2016), in order to obtain a better understanding of the activation pathway of ipRGCs cells