Graeme Whelan writes:
> It's not that we don't know why we sleep, it's just that it is difficult
> to prove.
Of course, everyone knows why we sleep. The real problem is that we do not
agree.
My simplistic reason for mammalian sleep is that it is part of the foraging
strategy written in the genome. The genome programs the organism to shut
down during that part of the daily (annual) cycle in which there is more
chance of being eaten than of eating or in which the energy expended exceeds
the potential energy taken in. The energy equation is balanced by
inactivating the forebrain and thus reducing the metabolism. The reticular
formation stays on to watch for the predator.
--
Ray
Those interested in how the brain works might look at
www.wsg.net/~rscanlon/brain.htm
> >The slow wave sleep (SWS) referred to is the time that growth hormone is
> >released at twice the normal rate and also the period during which
> >neurotransmitters are synthesized in the brain at up to four times the
rate done
> >at any other time. Ever wonder why we get a little fuzzy in our thinking
when
> >sleep deprived, have trouble with judgement and with co-ordination? The
immune
> >system also gets a boost while we are experiencing SWS.
> >
> >The rapid eye movement (REM) sleep appears to have very little to do with
> >consolidation of experience and more to do with establishing and
repairing
> >connections in the brain. A foetus at 26 weeks gestation spends 100% of
its
> >time in REM sleep, having had almost no 'experiences' to deal with and no
> >psychological dilemmas which Freud proposed as the function of dreaming.
A
> >new-born baby spends 10 of its 20 sleeping hours a day in REM sleep, this
amount
> >diminishing as the brain approaches its adult size.
> >
> >Total sleep deprivation will kill. There is a point of no return marked
by
> >hypothermia after which a person will die, no matter what sleep they are
allowed
> >and what care they are given after that point. This is the result of a
poorly
> >functioning immune system. True, the cause of these deaths was a mystery
for
> >many years, but it has been shown to be septicaemia. The mammals tested
min
> >these experiments were simply overwhelmed by the sheer number of bacteria
in
> >their bodies, hence the increasing energy consumption but decreasing
weight and
> >body temperature. Very difficult to detect when the responsible
organisms are
> >those that ordinarily inhabit the body and are totally benign. It just
goes to
> >show you won't see what you're not looking for.
> >
> >I was disappointed to see that the article below was from New Scientist.
I
> >would have expected more thorough research from such a journal. Clearly
they
> >needed a filler piece in a hurry and thought that naming a few related
> >disciplines and calling on the name of evolution - which we should
remember is
> >still a theory, not a fact - would create something to pass for a
credible
> >article.
> >
> >Graeme
> >
> >gwhelan at XXXaccess.net.au> >(remove the X's to reply)
> >
