Hypnos, 1 (Suppl 1): 100-110, 2004 NEURAL ARCHITECTURE OF CIRCADIAN RHYTHMS: A SUBSTRATE TO SLEEP-WAKE STUDIES Luciana Pinato, Eduardo Garcia Rodrigues, Luiz Fernando Takase and Maria Ines Nogueira Laboratório de Neurociências, Departamento de Anatomia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil Corresponding author M.I.Nogueira Laboratory of Neurosciences, Department of Anatomy Institute of Biomedical Sciences Universidade de São Paulo, 05508-900, São Paulo – Brazil Phone: +55-11 3091-7401 Fax: +55-11 3091-7366 e-mail: minog@usp.br Acknowledgments The authors acknowledge the technical support of Ms. C.R Prisco, proof reading by Mr. D. M Mardon, and grants, as fellowship and research support, from PRP-USP, CNPq, CAPES and FAPESP. Also the authors are immensely grateful to Dr. Marina Bentivoglio, Department of Histology and Embriology, Univ. di Verona, for patnership and goodwill. 100