Raunak Sinha, PhD
Assistant Professor, Department of Neuroscience, School of Medicine and Public Health University of Wisconsin-Madison
Research: “Understanding cone signaling in the fovea”
Research
Understanding cone signaling in the foveaOur everyday visual experience – including your ability to read this text – is dominated by signaling in the fovea. The first step in our high definition foveal vision occurs in the cone photoreceptors that are tightly packed in a hexagonal lattice forming an array of fine pixels. Such an arrangement together with the unusual morphology of foveal cones and downstream retinal circuitry is key for the high spatial and chromatic resolution attributed to our foveal/central vision. Even though, the anatomical specializations of foveal cones have been known for almost a century, our knowledge about their functional specializations is almost lacking. Our lab is interested in understanding i) the functional properties of foveal cones and differences across retinal locations and ii) specialization of the phototransduction cascade in the fovea. Our recent work (Sinha et al. Cell 2017) provided the first insight into how foveal cones operate at a cellular level and to our surprise, we found that their functional responses to light are unique and quite distinct from cones in other locations in the retina. The goal is to build on this initial observation and characterize the functional specialization of foveal cones at an unprecedented resolution from single molecules to cellular function and then use this in vivo information as a baseline for testing cone function in human stem cell-derived retina.
In addition to studying photoreceptor signaling, our lab is broadly interested in understanding how cellular, synaptic and circuit-level mechanisms mediate sensory processing in the retina that ultimately lead to visual perception. We pose this question in species that have varied retinal specializations and rely on vision to different degrees. We utilize electrophysiological recording and optical imaging to assay neuronal function. We correlate single cell activity with detailed anatomical analysis using light and electron microscopy. We use genetic tools to perturb cell function, express fluorescent probes, map retinal circuits and identify molecular mechanisms shaping cellular processes.
