Photo of Russ Hamer

Russell D. Hamer, PhD

Retinal Physiology and Computational Modeling

The initial event in vision is the reception of light by cells (photoreceptors) in the back of the eye, the rods ("night" receptors) and cones ("daytime" receptors). Although photoreceptor structure and function has been studied for more than a century, many fundamental details of their structure and function are not yet understood. The process by which photoreceptors convert light energy into electrical signals is called phototransduction, which begins with absorption of photons of light by pigment molecules (rhodopsin) in the receptor. Each activated rhodopsin molecule initiates a cascade of biochemical reactions that lead to an electrical response in the membrane of the cell, and transmission of that signal to the visual centers in the brain.

We are developing models of rod and cone phototransduction by developing mathematical expressions of the underlying biochemical reactions. The models are refined by comparing their performance with the actual responses of photoreceptors. The models can then be used to simulate biochemical experiments and to make predictions that can help guide future physiological and biochemical research.

Some questions addressed are:

Collaborators: Terry Hegarty, Spero Nicholas, Tsuyoshi Ohyama., Juan Korenbrot, Daniel Tranchina, Paul Liebman, Trevor D. Lamb.