1. Medicinal Chemistry Division, Cellular and Molecular Neurobiology Laboratory, and Cardiovascular Diseases Division, Centre de Recherche Pierre Fabre, 17 Avenue Jean Moulin, 81106 Castres Cédex, France, and Laboratory of Amino-acids, Peptides and Proteins, Faculté de Pharmacie, University of Montpellier I et II, 15 Avenue Charles Flahaut, 34060 Montpellier Cédex, France