ABSTRACT
Mendelson et al. reinvestigated sleep-inducing properties of some candidate substances including Delta-Sleep-Inducing Peptide, Factor S, and sleep-promoting substance by their own methods and concluded that none of the currently available factors have been convincingly shown to be physiologic mediators of sleep. The modem study by Kornmuller et al. opened a new epoch of research for sleep substances. By that time, the objective technique of electroencephalogram monitoring was available. Since then, the Swiss researchers established an extracorporal dialyzing technique to obtain hemodialyzates from the venous blood of sleeping rabbits electrically stimulated in the thalamic “sleep center”. Koella schematized the input-output relations in the sleep-waking regulatory system. Sleep factors may carry information about the present state and the recent history of the central nervous system and also chronological signals delivered by the biological clock. The chapter also presents an overview of the key concepts discussed in this book.
