1. Department of Biology, Wilfrid Laurier University, 75 University Ave. W., Waterloo, Ontario N2L 3C5, Canada
2. Department of Biology, McMaster University, 1280 Main Street W., Hamilton, Ontario L8S 4K1, Canada
3. Department of Physiology and Pharmacology, Western University, 1151 Richmond Street, London, Ontario N6A 5C1, Canada