1. Department of Pharmacology-Physiology Faculty of Medicine and Health Sciences and Institut de Pharmacologie de Sherbrooke Université de Sherbrooke Sherbrooke J1H 5N4 Québec Canada
2. Department of Medicine Faculty of Medicine and Health Sciences Université de Sherbrooke Sherbrooke J1H 5N4 Québec Canada
3. Current address: Department of Biology Faculty of Sciences Université de Sherbrooke Sherbrooke J1K 2R1 Québec Canada
4. Current address: Xenon Pharmaceuticals Inc. Burnaby V5G 4W8 British Columbia Canada
5. Department of Microbiology and Immunology Faculty of Science Life Sciences Institute University of British Columbia V6T 1Z3 British Columbia Canada