1. GlaxoSmithKline Medicines Research Centre, Verona, Italy
2. Biological Reagents and Assay Development, GlaxoSmithKline Medicines Research Centre, Stevenage, UK
3. Gene Cloning Group, Discovery Technology Group, Molecular Discovery Research, GlaxoSmithKline, Upper Providence, PA, USA
4. Consiglio Nazionale delle Ricerche, Institute of Neuroscience, Cellular and Molecular Pharmacology Center, Department of Medical Pharmacology, University of Milan, Milan, Italy