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The influence of gravity on REM sleep

Authors Gonfalone A, Jha S

Received 10 January 2015

Accepted for publication 26 February 2015

Published 22 May 2015 Volume 2015:7 Pages 65—72


Checked for plagiarism Yes

Review by Single-blind

Peer reviewer comments 5

Editor who approved publication: Dr Peter Koulen

Alain A Gonfalone,1 Sushil K Jha2

1European Space Agency, Paris, France; 2School of Life Sciences, Jawaharlal Nehru University, New Delhi, India

Abstract: It is suggested that environmental variables, and gravity in particular, are the main determinants of sleep duration. Assuming that the rapid eye movement (REM) sleep state depends on the influence of gravity allows a better understanding of sleep across the animal world. This paper is based on numerous results already published on sleep behaviors, sleep postures, sleep durations, and the weights of many species. The difference between the sleep behavior of aquatic animals and terrestrial mammals is explained by the effect of gravity in different environments: ocean or land. Archimedes' principle applied to aquatic animals shows that their weight is minimal and this may explain the lack of REM sleep. The fact that cats or rats in unsafe positions above water do not experience REM sleep is explained by the fear of atonia, a complete relaxation of the antigravity muscles, which happens during REM sleep, completing the process of reduced sensitivity to the environment: light, sound, contact, etc. Furthermore, a very clear dependence of sleep duration on weight is obtained when plotting the data for 76 terrestrial mammalian species, showing that sleep and gravity are related. Another dependence of sleep duration, on gestation time, is presented, and this shows the difficulty of interpreting sleep and its relation to a single parameter.

Keywords: weight, atony, mammal, dream

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