1. Development of the Nervous System, IBENS, Ecole Normale Supérieure, 46 rue d’Ulm, 75230 Paris Cedex 05, France
2. Biochemistry Center, University of Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
3. IPREM, University of Pau, 2 rue du President Angot, 64000 Pau, France
4. Instituto Tecnologia Quimica e Biologica, Universidade Nova de Lisboa, Avenida da República, EAN, 2784-505 Oeiras, Portugal