Talk:Sleep in animals
The author presents a very readable chapter on sleep in animals. His conclusion appears to be that sleep results from animals need to deal with the consequences of waking metabolic activity, especially the effects of reactive oxygen species. This is a reasonable hypothesis, and it is well-supported by some of the examples put forth. In addition, the author clearly lays out some of the inconsistencies attached to other sleep theories, such as to consolidate learning. A few striking examples in the mammalian literature make us reconsider the validity of such hypotheseses. It is very useful to be reminded of these, and in this way the article is excellent. For example, the decreased sleep need in herbivores coupled to their lower arousal thresholds (they do not sleep deeper when they sleep) is hard to reconcile with some general sleep theories put forth by other investigators. The negative correlation with body mass makes some sense, as we are reminded here. Altogether, this is a good article. Also, the platypus examples, or the issue of immature births and REM sleep. This is all required reading for any researcher interested in sleep.
There are a few other issues worth considering, however. The conundrums offered by the author are all restricted to mammals. One might imagine that we should resolve these before addressing other conundrums in other animals. But, considering sleep in other animals such as birds, reptiles, fish, or even insects might actually help address some of the issues put forth by the author. By focusing mainly on brain activity measures (EEG) as an indicator of sleep, and less on arousal thresholds across the animal kingdom, the author may have missed an opportunity to fully investigate these exciting questions in a thorough manner. For example, insects sleep but show neither REM nor slow-wave activity in their brain. This must somehow be reconciled with the general views put forth by the author (e.g., brainstem activation), as well as considering oxidative stress hypotheses in a simple animal with regard to sleep. Why should a fly require as much sleep as a human? This is perhaps a larger conundrum than the examples within mammals brought up by the author.
Perhaps this venue (Scholarpedia) is the ideal one for furthering this debate and lengthening the article. As it stands, it was a very useful article to read and should most definitely be published here.
Author :
Thank you for your comments. I agree that the title should be restricted to mammals and also that the examples in nonmammalian species are relevant. I cannot do both since I was asked to keep to a word limit. I will continue to suggest other readings to cover these issues.Once this articel is accepted, I may attempt to expand it time and editor permitting. JS
