Restitution and human sleep: A critical review

Abstract

It is often assumed that human non-REM sleep, especially its apparently more intense form of slow-wave sleep (SWS), is associated with large increases in body restitutional processes, for example, protein synthesis. However, findings from total sleep deprivation appear only to support a brain restitutional role for human sleep and not one of body restitution. Although rises in human growth hormone (hGH) release during SWS might support a body restitutional role, the variety of complex actions of hGH indicate that other effects, particularly the redistribution of energy substrates, are likely. Sleep hGH release may be a misleading factor in the understanding of SWS function. Increases in protein synthesis during human sleep are unlikely for several reasons. The elevation of mitosis which can occur in sleep is probably a concomitant phenomenon. While relaxed wakefulness should provide for man’s body restitutional need, the lack of such a relaxed state in certain mammals may necessitate that sleep fulfills this need for these animals. Although REM sleep, alone, is generally considered to be for cerebral restitution, evidence in support of this viewpoint needs qualification. It is argued that non-REM sleep, especially SWS, is of equal benefit to the human brain. © 1979, Psychonomic Society, Inc.. All rights reserved.