Regulation of physiology and behavior by light.

The Do lab takes a biophysical approach to investigating the mammalian visual system, primarily by applying electrophysiological and optical techniques to in vitro neural tissue. They focus on two neural pathways. The first employs unusual photoreceptors; these are not the classical rods and cones, but rather a population of retinal output neurons that capture light with a molecule called melanopsin. These intrinsically photosensitive retinal ganglion cells drive "non-image" visual functions such as the regulation of sleep, circadian rhythms, and hormone levels. The second pathway is that of the fovea. It produces an exceptionally detailed and dynamic representation of the visual image, using processes that remain to be understood. They study the mechanisms of signal generation in these pathways and interpret them in the context of behavior. Both of their research topics have implications for human health. The melanopsin pathway, by serving as the principal regulator of the circadian clock, is responsible for setting the normal pattern of gene regulation throughout the body. Circadian dysregulation has been implicated in jet lag, metabolic disorders, cancer, and other ailments. The melanopsin pathway also exerts a direct influence on alertness, sleep, and hormone levels. The fovea is destroyed in macular degeneration, the leading cause of blindness in developed nations. Understanding the normal physiology of these systems is a key step toward maintaining and repairing them.