Sleep / REM Sleep and homeostasis

DanP

Physiology texts indicate that an animal deprived of sleep will face homeostasis disturbances, for example they can loose weight despite an increased caloric intake, and they will eventually die.

An animal deprived of REM sleep for several sleeping sessions in a row will show increased REM activity during subsequent sleep. Interrupting REM sleep repeatedly shows same disturbances in homeostasis as general sleep deprivation.

1. What is the role of the sleep in homeostasis . What is the mechanism ?
2. Is REM sleep essential in primates for homeostasis ? If yes, why, and what effects it mediates in addition NREM sleep stages.
3. Is there any correlation between total period of REM sleep in an adult and accumulated fatigue? For example, would an athlete who just competed in a probe like 100m sprint which requires maximum activation of motor cortex show significant increased REM sleep total time in the following sleep period? If yes, does it stand significant on its own , or it is just a consequence of longer total sleep ?

Just pointing to relevant reading materials is ok for an answer . Thanks

Moonbear

You're asking excellent questions. Unfortunately, there aren't a lot of excellent answers available. Those questions are active areas of research. While it's well recognized that we do need sleep, it's a lot less understood WHY we need sleep. It's more than a need to rest, because people can rest and remain somewhat immobile, but if they don't sleep, they still don't function right. Another question being asked is why does there seem to be a function not just for total amount of sleep, but how contiguous the sleep espisodes are? For example, you can get the same total amount of sleep either all at one time or you can take a lot of naps that all add up to the same amount of sleep. They don't have the same effect on your body's ability to function physically or cognitively.

granpa

carl jung wrote about 'directed thinking' and 'symbolic thinking' (dreaming). directed thinking is tiring and we need from time to time to dream to recharge our batteries.

as for homeostasis couldnt it simply be that the animals are tense and restless so they burn more calories?

I believe that we dream even in nrem sleep. during nrem sleep we watch the dream like we would watch tv. we are still sufficiently 'with it' to realize that it isnt real. its only during rem sleep that we believe that its real and start taking part in whats happening. thats why our body becomes paralyzed during rem sleep