1Department of Electrical Engineering, Stanford University, Stanford, CA 94305 USA
2Department of Neurobiology, Stanford University, Stanford, CA 94305, USA
3Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA
4Department of Biological Sciences, Stanford University, Stanford, CA 94305 USA
5Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305 USA
6Department of Applied Physics, Stanford University, Stanford, CA 94305 USA