[1] Salk Inst Biol Studies, Syst Neurobiol Labs, La Jolla, CA 92037 USA
[2] Univ So Calif, Keck Sch Med, Dept Cell & Neurobiol, Zilkha Neurogenet Inst, Los Angeles, CA 90033 USA
[3] Carl von Ossietzky Univ Oldenburg, Dept Neurosci, D-26129 Oldenburg, Germany
[4] Univ Strathclyde, Inst Photon, Glasgow G4 0NW, Lanark, Scotland
[5] Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA
[6] Stanford Univ, Dept Neurosurg, Stanford, CA 94305 USA
[7] Stanford Univ, Hansen Expt Phys Lab, Stanford, CA 94305 USA