This paper is dedicated to our mentor, Michel Jouvet who inspired our career and transmitted to us his passion for the study of the mechanisms responsible for paradoxical sleep genesis and also that of its still mysterious functions. We expose in the following the progresses in the knowledge in this field brought during 40 years by Michel Jouvet and his team and more recently by the members of a new CNRS laboratory in which we aim to pursue in the path opened by Michel Jouvet
