1. Department of Pharmacology and Therapeutics, McGill University, McIntyre Medical Building, 3655 Promenade Sir William Osler, Room 1215, Montreal, Quebec H3G 1Y6, Canada
2. Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec H3A 0G1, Canada
3. Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada