ABSTRACT

Pieron was the first to introduce the concept and experimental evidence for a chemical factor that would presumably accumulate in the brain during waking and eventually induce sleep. This concept lay dormant for many years, in the absence of adequate techniques and knowledge to pursue the identification of such a hypnogenic factor. With the development of biochemical techniques and the description of various neurotransmitters with specific anatomical localization, it was suggested that these chemicals could be normally involved in the generation of sleep. Michel Jouvet in the 1960s championed the concept that sleep and waking could be, respectively, generated by specific chemical neurotransmitters contained in specific neuronal systems.