[Long and difficult way towards the understanding of sleep function. Period before the age of electrophysiology].

It was proposed that historical analysis of ideas concerning the function of sleep will help to evaluate the tendencies in this field of science and will show the probable direction for further approach to understanding of this problem. We reviewed ideas of Ivan Pavlov and his Russian forerunners (Ivan Tarkhanoff and Maria Manaceine) and followers (Nikolay Rozjanskiy and Konstantin Bykov) on the functional role of sleep. This analysis led to the conclusion that state of sleep have been connected with realization of such functional operations, which have not been considered in the past and are not under consideration in the present neuroscience. Thus, one can expect that real understanding of sleep function will come only with new neurophysiologic paradigm.