Concepts of Neurophysiological Factors in the Central Regulatory Mechanism of Non-Rapid Eye Movement Sleep: A Review

Abstract

Objective: It is now fully ascertained that the generation of non-rapid eye movement sleep (NREM) involves vital brain processes achieved through complex interactions of underlying neurophysiological factors, including those of the mechanism for the production of the behavioral expressions of NREM sleep. These central processes in the mechanism of NREM sleep are still far from clear and are subject of much speculations and even controversy. It was the aim of this review to identify and assemble those factors in brain function that informed current research postulations of workers in the subject of the production of NREM sleep. Methods: Information gathering adopted in this review included, articles and published research works, seminars and conference articles on sleep, information from current textbooks in neuroscience on sleep, lecture notes in behavioral neurophysiology and biology, and articles and reports on sleep accessed from the Internet using search engines such as Google, PubMed etc., were all sources of information consulted. Results: The significance of specific neurotransmitter systems – Serotonin, GABA and Adenosine, in the proposed central mechanism for the production and behavioral expressions of NREM sleep have been clearly highlighted in this review. Facts noted in this review successfully sensitized the attention of research to the growing profile of the more recently identified Metabolic Energy substrates Drive in the proposed possible central mechanism for the generation of NREM sleep stage. Conclusion: Research postulations and proposals assembled in this review appear generally to support the notion that different brain processing networks and neurochemical units are probably involved in the production of NREM sleep and other distinct states of sleep. It is therefore concluded from this review that probably different neuronal pathways and systems make up specific vital brain processes for the production and expressions of NREM sleep stage, and these central processes are still far from fully understood with certainty.