Steven A. Baccus






		Steven A. Baccus, Ph.D. Title Assistant Professor Department Neurobiology Research Interests Visual processing in neural circuits of the retina, studied using multielectrode extracellular array recording, intracellular recording, imaging, and computational modeling. Email mailto:baccus@stanford.edu Phone 736-1512 Fax 725-3958 Address Fairchild D209 Mail code: 5125 Faculty Research Description We study how the circuitry of the retina translates the visual scene into electrical impulses in the optic nerve. Visual perception is initiated by the molecules, cells and synapses of the retina, acting together to process and compress visual information into a sequence of spikes in a population of nerve fibers. One of the largest gaps in neuroscience lies in the explaining of systems-level processes like vision in terms of cellular-level mechanisms. This problem is tractable in the retina because of its experimental accessibility, and the substantial amount already known about basic retinal cell types and functions. Our goal is to explain specific retinal visual processes such as adaptation to contrast, the encoding of brightness, and the detection of moving objects. To do this, we use a versatile set of experimental and theoretical techniques. While projecting visual scenes from a video monitor onto the isolated retina, an extracellular multielectrode array is used to record a substantial fraction of the output of a small patch of retina. Simultaneously, we record intracellularly from retinal interneurons in order to monitor and perturb elements of the circuit as it operates. Additionally, we use laser-scanning imaging as a way to access subcellular neural structures. Finally, all of this data is assembled and interpreted with mathematical models in order to predict and explain the output of the retinal circuit. Representative Publications Baccus, S. A. & Meister, M. 2004. Retina versus cortex: Contrast adaptation in parallel visual pathways. Neuron. 42: 5-7. Olveczky, B., Baccus, S. A. & Meister, M. 2003. Segregation of object and background motion in the retina. Nature 423: 401-408. Baccus, S. A. & Meister, M. 2002. Fast and slow contrast adaptation in retinal circuitry. Neuron, 36: 909-919. Areas of Study Systems/Behavioral Neuroscience Cellular Neurobiology Membrane Excitability SBRC PhD

Steven A. Baccus, Ph.D.