1. Bioengineering Option, California Institute of TechnologyPasadena, CA 91125-4100, USA
2. Department of Physiological ScienceUniversity of California1804 Life Sciences, 621 Charles E. Young Drive South, Los Angeles, CA 90095-1527, USA
3. Mechanical Engineering Option, California Institute of TechnologyPasadena, CA 91125-4100, USA
4. Brain Research Institute, University of CaliforniaLos Angeles, CA 90095, USA
5. Department of Neurobiology, University of CaliforniaLos Angeles, CA 90095-1763, USA