Harvard Catalyst Profiles

Harvard Medical School, Boston, MA	PhD	2004	Neurobiology
Johns Hopkins University School of Medicine, Baltimore, MD	Postdoc	2011	Neuroscience

Our lab asks how light drives functions that are as diverse as visual perception and setting of the internal body clock. We pose this question for different species to learn how visual mechanisms are tailored to distinct needs. Our research spans organizational levels and time scales, from molecules to circuits and from milliseconds to hours. We focus on the retina and brain, relying primarily on electrophysiological and optical techniques applied in vitro and in vivo.

Visual performance is remarkable. Perception can be elicited by a small number of photons, yet continues when light has intensified by many orders of magnitude. How is this dynamic range established? In cases of severe blindness where visual awareness is lost, light can still synchronize the body clock with the solar day. What are the origins of this robustness?

Such questions of system function apply throughout biology. Posing them in the visual system is advantageous because the input, light, is precisely controllable and the outputs, such as the patterns of impulses sent from the eye to the brain, are often given to quantification. Thus, the intervening operations and their suitability to the organism can be made especially clear.