1. Department of Neurology and Neurological Sciences, Stanford Medical School, Stanford, CA 94305, USA.
2. Behavioral and Functional Neuroscience Laboratory, Stanford Medical School, Stanford, CA 94305, USA.
3. Department of Biology, Stanford Medical School, Stanford, CA 94305, USA.
4. Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA.