Host: University of Southern California
The topic that Rhaul is studying is Rhodopsin Biosynthesis and Disc Formation in Rod Photoreceptor cell Description: Photoreceptor cells are a specialized type of neuron found in the retina that absorb and convert photons into electrical signals. They are essential for initiating the phototransduction cascade, which ultimately leads to visual perception. There are two types of photoreceptors: rods and cones. Rods are located in the outer regions of the retina and allow us to see in dim light as well as dark conditions. Rhodopsin is the light sensitive visual pigment in rods that allows humans to see in these low light conditions. Cones, on the other hand, reside mostly in the central portion of the retina and allow us to perceive fine visual detail and color. Both rods and cones are comprised of an outer segment full of discrete membranous discs, an inner segment, a nuclear layer, and a synaptic terminal. My project focuses on understanding rhodopsin biosynthesis and disc formation patterns in rod outer segments (ROS). It is widely accepted that disc formation in mammalian rods follows a 10-day cycle and light exposure increases disc phagocytosis at the apical end and increases lipid production at the basal end. Phagocytosis and degradation of ROS ensures functional integrity of the photoreceptor cells and other retinal cells. There are several factors, such as genetic or environmental factors, that can cause photoreceptor degeneration and eventual vision loss. Currently I am exploring how varying light conditions impact ROS renewal and rhodopsin incorporation into discs. Using a transgenic mouse that has a fluorescent marker attached to rhodopsin, I aim to understand the pattern of disc formation, rhodopsin biosynthesis in ROS, and the degenerative effect of light. This project can provide insight on how light exposure affects photoreceptors structure and function, which plays a key role in the visual process.