Current Concepts in the Neurophysiologic Basis of Sleep; a Review

BACKGROUND: Sleep is a very vital physiological mechanism, which involves complex interactions in the nervous system. These interactions are not well understood and have been a subject of controversy in contemporary medical practice. OBJECTIVES: To review of the neurophysiological factors in the subject of sleep, and recent research findings that forms the basis for the current knowledge on sleep. METHODS: Information sources consulted included, published works of past researchers, current articles on sleep in conference papers, recent editions of textbooks on neuroscience, articles in seminar papers, reports extracted from newspaper and magazine articles on sleep, reports accessed from the Internet using Google Search Engines and lecture notes. RESULTS: It was noted that emphasis has now shifted from the concept that sleep was predominantly the product of activities in the neural systems in phylogenetically old reticular core of the brain through withdrawal of sensory input, to emphasis on the role of neurotransmitter systems, especially - Ach, serotonin and GABA. This review also noted that, among others, emphasis is further shifting to the PGO waves which is fast gaining prominence as the mechanism involved in the production of REM sleep and dreams in particular. CONCLUSION: It became obvious from this review, that full knowledge of the neurophysiological processes involved in sleep production appear generally to still be more of speculative, and are yet far from full understanding.