[Neuroscience] Re: why did humans grow a bigger neocortex?
(by bingblat from goaway.com.au)
Thu Jul 26 21:54:53 EST 2007
"Entertained by my own EIMC" <write_to_eimc from ozemail.com.au> wrote in message
news:46a84d24$0$31439$5a62ac22 from per-qv1-newsreader-01.iinet.net.au...
> Hi John,
> You write write really well about what's wanting - and you write with
> admirable specificity.
> I _do_ agree with you - given the way you presented the problems of
> understanding things.
> Since I got the sense that the amyloidal protein tangles that appear to be
> part of the structural symptoms of Alzheimer's disease loomed large
> (associatively only - nothing else!) in your lobes when you wrote what's
> below, I will say this:
> I think a very well hedged bet on what is a key contributory cause of
> Alzheimer's (however, I could quite easily place the same kind of bet in
> several other baskets too) is some conditioned-in source of stress that
> (or that in the case of certain genomes can have) this kind of of
> "camel's-back-braking" effect.
Yes, there is a molecular underpinning to this. Specifically,
glucocorticoids can induce the expression of amyloid. What needs to be
studied here is how glucocorticoids affect the balance of amyloids 1-40,
1-42. Interestingly the hippocampus is amongst the first regions to be
affected by neurodegeneration and this region is very rich in gc receptors.
Ongoing stressors throughout the day will also induce spikes in
pro-inflammatory mediators which are probably contributing to amyloid
expression. So we should not be too surprised at an epidemic of dementias
because we live in a peaceful yet very stressful culture.
> Of course I would prefer to call this conditioned-in source of stress
> "CURSES in the actention selection serving system" rather than "Pain, or
> primal pain, in the brain".
> I don't think we will be so lucky that we end up discovering that
> as simple as virus (that has some vulnerability that allow us to vaccinate
> against it) is the cause.
There are many paths to enlightenment and there are many paths to dementias.
Genetic predisposition doesn't figure that highly except for the early onset
Alz, overall environmental factor appear far more determinative. Sustained
systemic inflammation, head injury (even a few mild concussions), bad stress
management, poor diet, pollution, heart disease, diabetes, poor sleep,
chronic circadian disruption, lack of exercise .... . I sometimes get the
impression that we are too preoccupied looking for a specific cause, there
are many causes and there may not be a final common pathway but many
> "John H." <bingblat from goaway.com.au> wrote in message
> news:13ag9puldh0ae2 from corp.supernews.com...
> > Peter,
> > The problem is beyond me because the data is too scant and I lack
> > imagination. I have read various papers purporting to model metabolic
> > processes and sometimes these models are remarkably accurate but only in
> > particular instances not as a global understanding of any physiological
> > function. The problem is compounded by the fact that very few studies
> > address the issue of substrate availability, which to my mind becomes a
> > determinative factor in situations of high transcriptional activity.
> > there was the recent paper claiming the protein construction is not just
> > DNA\RNA dependent, that lipid composition of various organelles, and
> > probably the cell membrane, impact on the final folding processes. The
> > quality control process for protein generation is quite beautiful yet
> > under
> > optimal conditions approx 10% of all proteins must be degraded due to
> > malformation. This is where the whole business of protein tangles etc
> > becomes very important, a failure of the degradation pathways is
> > a
> > key factor driving protein tangle formation. It is possible to write
> > and pages about it but at the end of it all we just have lots of dangly
> > bits, no coherent picture of what is going on. That probably won't
> > in
> > my lifetime.
> > So despite all the wonderful and painstaking research we are still only
> > just
> > beginning.
> > "Entertained by my own EIMC" <write_to_eimc from ozemail.com.au> wrote in
> > message
> > news:46a1636b$0$12853$5a62ac22 from per-qv1-newsreader-01.iinet.net.au...
> >> "John H." <bingblat from goaway.com.au> wrote in message
> >> news:13a0irkf8ae5n8b from corp.supernews.com...
> >> > "Since the brain is unlike any other structure in the known universe,
> >> > it
> >> > seeems reasonable to expect that our understanding of its
> > if
> >> > it can ever be achieved - will require approaches that are
> >> > different from the way we understand other physical systems."
> >> >
> >> >
> >> > The Brain: The Last Frontier. Restak, RM, Garden City, NY. Doubleday
> > 1979
> >> >
> >> > Now there's synchronicity for you, I just read that not ten minutes
> >> > ago.
> >> > Not
> >> > really happy with Restak's comment but I take his drift. I think it
> >> > apply to more than just the brain, it seems to me that physiology in
> >> > general
> >> > is loaded with multitudes of mysteries and that our understanding of
> >> > biological processes en masse requires a cognitive overhaual. So the
> >> > problem
> >> > may be much deeper than I care to think about, which means I'm too
> > stupid
> >> > for the task. I can see the problem but I can find no way of
> >> > it.
> >> >
> >> Hi John,
> >> Although, to me, you are okey as you are, here is a suggestion:
> >> Perhaps you can't find it (whatever "it" is, to you) because you are
> > looking
> >> in a way that is just a tiny bit wrong, and in places that are just not
> >> quite the right ones!? %-)
> >> If it is so, you might be well served by taking several steps back
> >> surveying (still in your usual science-aligned way) 'the stage' (as if
> >> you
> >> were an assuage seeking aussie sage) in cognitive combination with a
> >> deliberate (if need be *forced on yourself by your self* ;->)
> > philosophical
> >> application of a tolerance principled (Uncertainty Principle-related)
> >> attitude.
> >> This way you might end up (through the method of 'analytical
> > in
> >> an approximately all-knowing (or, in the proximity of an omniscient -
> >> not guaranteed to be perfectly agreeable) _personal_
> > rational-philosophical
> >> state of What Is going on.
> >> Cheers,
> >> P
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