[1] Univ Colorado, Dept Chem & Biochem, Campus Box 215, Boulder, CO 80309 USA
[2] Univ Colorado, BioFrontiers Inst, Boulder, CO 80309 USA
[3] Univ Colorado, Dept Psychol & Neurosci, Boulder, CO 80309 USA
[4] Univ Colorado, Ctr Neurosci, Boulder, CO 80309 USA
[5] Scripps Res Inst, Dept Integrat Struct & Computat Biol, 10550 North Torrey Pines Rd, La Jolla, CA 92037 USA
[6] Scripps Res Inst, Skaggs Inst Chem Biol, 10550 North Torrey Pines Rd, La Jolla, CA 92037 USA