Joanne SM Kim1,2
, Brendan N Lilley3
, Chao Zhang4
, Kevan M Shokat4
, Joshua R Sanes3
and Mei Zhen1,2 
1Department of Molecular Genetics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
2Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, M5G 1X5, Canada
3Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
4Howard Hughes Medical Institute and Department of Molecular and Cellular Pharmacology, University of California, San Francisco, CA 94143, USA