1. Neurogenesis and Brain Repair Group, Neurobiology Program, Institute for Biological Sciences, National Research Council Canada, 1200 Montreal Rd., Bldg. M-54, Ottawa, ON K1A 0R6, Canada.
2. Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
3. Functional Polymer Systems Group, Industrial Materials Institute, National Research Council Canada, Boucherville, QC J4B 6Y4, Canada.
4. Division of Neurosurgery, Children’s Hospital of Eastern Ontario, Ottawa, ON K1H 8L1, Canada.