Classes - Cellular and Molecular Neuroscience, Topics: Nature and Nurture
The retinas in your eyes are not just for seeing! While most of the millions of retinal cells are involved in processing visual information and relaying that information to the brain, a small population of cells has a simpler job: reporting how bright the environment is to the brain. These cells are called melanopsin retinal ganglion cells, or mRGCs for short. Each mRGC is itself a photoreceptor, capable of responding to light without any input signals derived from the photoreceptors that contribute to vision, rods and cones.
Signals from mRGCs have a profound impact on animal behavior, as they are the primary sensory input to our body’s internal clock, the suprachiasmatic nucleus. This clock controls our daily (i.e. circadian) rhythms, including sleep-wake cycles, alertness, and much of metabolism. Misalignment of sensory input from mRGCs and daily behavior has profound health consequences. For example, shift workers are at a substantially elevated risk for type II diabetes and depression.
Despite being intrinsically sensitive to light, mRGCs receive extensive input from other retinal neurons. The goals of the lab include examining the development of these inputs onto mRGCs and determining their role in computing light levels. We also collaborate with scientists at the Salk Institute in La Jolla, CA studying melanopsin phototransduction. The long-term goal of this work includes developing molecular genetic tools for restoring visual function in patients with some forms of blindness, notably age-related macular degeneration. The tools we use include electrophysiology, microscopy, mouse genetics, and behavioral analysis.