1. Neuroscience and Pain Research Unit, Pfizer Ltd.; The Portway Building, Granta Science Park Cambridge CB21 6GS UK
2. Department of Pharmacology, Biomedical Research Centre (CIBM) and Institute of Neuroscience, Faculty of Medicine; University of Granada; Granada Spain
3. National Centre for Bowel Research and Surgical Innovation, Blizard Institute, Barts and the London School of Medicine and Dentistry; Queen Mary University of London; London E1 2AT UK
4. Department of Biochemistry, Biomedical Research Centre (CIBM) and Institute of Neuroscience, Faculty of Medicine; University of Granada; Granada Spain
5. Molecular Nociception Group, Department of Biology; University College London; Gower Street London WC1E 6BT UK