1. Neuroscience Program, Stanford University, Stanford, CA 94305, USA.
2. Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
3. Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA.
4. Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA.
5. Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA.