Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!lll-winken!iggy.GW.Vitalink.COM!widener!netnews.upenn.edu!pender.ee.upenn.edu!rowe From: rowe@pender.ee.upenn.edu (Mickey Rowe) Newsgroups: sci.bio Subject: Re: Echidnas & REM sleep Message-ID: <42176@netnews.upenn.edu> Date: 29 Apr 91 02:35:53 GMT References: Sender: news@netnews.upenn.edu Reply-To: rowe@pender.ee.upenn.edu (Mickey Rowe) Organization: University of Pennsylvania Lines: 49 Nntp-Posting-Host: pender.ee.upenn.edu In article tomh.bbs@shark.cs.fau.edu (Tom Holroyd) writes: >In humans: ... >Deep sleep EEG is synchronized. Periodically, during sleep, the >cortex becomes active (desynchronized) accompanied by rapid eye >movements (REM), PGO spikes, etc. (Hippocampal theta, too, I think). etc. ... >Synchronized EEG is a lower dimensional state than desynchronized >EEG. The system doesn't wander around much, it mostly stays where >it is, or drifts around slowly. The active cortex, on the other hand, >is high-dimensional - there are many more degrees of freedom available >to the system. >Comments? I'm forwarding your post to a friend of mine who works in Adrian Morrison's lab... Hopefully I can get her to respond to this since she will likely give a better informed opinion. In the meantime you'll have to settle for me :) (though I'd also suggest that you might want to repost your original article to bionet.neuroscience). I'm guessing from your post that you feel that the purpose of sleep is to put cortex into a state of low activity. If you feel that this is in order to give neurons a chance to rest, I have to tell you that I've never met *anyone* who took that idea seriously. Frankly, I think that even if Francis Crick is a bit removed from reality, his ideas about the purpose of REMS seem a bit more likely. Current consensus amongst sleep researchers is that sleep is a very active period for nervous systems, and I suspect that you'd be hard pressed to find any of these people to agree that REMS exists to jolt the inactive brain closer to a waking state. There's quite a bit of literature on what's happening in sleeping brains if you'd like some names to look into. Forgive me for assuming that you might not be familiar with other ideas, but your analysis appears to me to be a bit shy on the side of biology... >Tom Holroyd >Center for Complex Systems >Florida Atlantic University >tomh@bambi.ccs.fau.edu Mickey Rowe (rowe@pender.ee.upenn.edu)