Our lab studies the visual signaling pathway in retinal rod and cone photoreceptors. Vision begins upon absorption of light by the visual pigment, is amplified by a series of highly regulated biochemical reactions, and ultimately results in closure of ion channels and membrane hyperpolarization.

This phototransduction pathway in rods is the best understood G-protein-coupled receptor signaling system known, particularly the activation phase of the light response. Much less is known about the recovery and adaptational processes of rod photoreceptors to light stimulation. Furthermore, our knowledge of the cone visual transduction pathway lags far behind what is known about rod phototransduction.

Our lab studies the regulation of cGMP metabolism in retinal photoreceptor cells (particularly PDE6), using a variety of molecular, biochemical, cell biological, and pharmacological approaches (see Research section). Because precise regulation of cGMP metabolism is critical for the visual signaling pathway, any defect in the processes controlling cGMP levels can have serious consequences, including visual impairment, retinal degeneration, and total blindness. Ultimately, our work will contribute to the development of therapeutic approaches to intervene in retinal diseases resulting from defects in the visual signaling pathways in rods and cones.