1. Institute of Bioimmagini e Fisiologia Molecolare, C.N.R., Segrate, Milan, Italy
2. Department of Pharmacology, Chemotherapy and Medical Toxicology, University of Milan, Milan, Italy
3. Department of Psychology, University of Oviedo, Oviedo, Spain
4. Department of Biochemistry and Molecular Biology, University of Oviedo, Oviedo, Spain