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From: tomh.bbs@shark.cs.fau.edu (Tom Holroyd)
Newsgroups: sci.bio
Subject: Re: Echidnas & REM sleep
Message-ID: <619614w163w@shark.cs.fau.edu>
Date: 29 Apr 91 15:32:40 GMT
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Sender: bbs@cs.fau.edu (Waffle BBS)
Organization: Florida Atlantic University
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> 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.
I'd say that, in the absense of input, the natural state of the cortex
is low activity, synchronized.  The cortex needs input to desynchronize it.
There is reduced input during sleep, hence more oscillatory behavior.
> 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. 
From what I've read, it's difficult to get sleep researchers to agree. :-)
I'm speaking from the point of view of dynamical systems.  If the cortex
remains in a limit cycle state for too long, it may be difficult for
it to escape.  This implies facilitation of the pathway.  On the other
hand, if the pathway habituates, it may cause a shift to another, related
limit cycle, with no more dimension than the first.

I have gotten a response from someone who said there was only one
experiment done to show that echidnas have no REM sleep, and the
animal may have been hibernating, not sleeping!  This brings up
the question of whether hibernating animals in general have REM
sleep or not.  I don't know.

Tom Holroyd
Center for Complex Systems
Florida Atlantic University
tomh@bambi.ccs.fau.edu