Brain surface

kenneth collins kenneth.p.collins at worldnet.att.net
Thu Nov 25 18:01:40 EST 2004


Newly-added comments, below,
constitute a case-in-point re. my
immediately-prior discussion :-]

"kenneth collins" <kenneth.p.collins at worldnet.att.net> wrote in 
message 
news:Fhtpd.58995$7i4.53709 at bgtnsc05-news.ops.worldnet.att.net...
| "Matthew Kirkcaldie" <m.kirkcaldie at removethis.unsw.edu.au> wrote 
in
| message
| 
news:m.kirkcaldie-13BA9A.12442325112004 at tomahawk.comms.unsw.edu.au...
|| In article <u24op0her5t9ss5tblv8kgei6nr7df5q0b at 4ax.com>,
|| r norman <rsn_ at _comcast.net> wrote:
|| > The traditional mediators of increased
|| > local circulation include "metabolites"
|| > like decreased pO2, increased pCO2,
|| > increased extracellular [K+] and
|| > adenosine. Any number of cellular
|| > metabolic processes produce the
|| > first two: nerve activity resulting in
|| > increased Na/K pump activity is
|| > certainly a leading candidate.  The
|| > same nerve activity will also increase
|| > K+.  These factors would readily
|| > diffuse over distances up to 1 mm.
|| > The pO2 and pCO2 changes would
|| > readily cross glial cells, probably a
|| > pH change could also, although the
|| > astrocytes may shield arterioles from
|| > K+ changes.  However, you could
|| > easily imagine that whatever metabolic
|| > effect controls arteriolar dilation would
|| > be something that the astrocytes were
|| > adapted to pass through rather than
|| > shield.
|| >
|| > Using up ATP most definitely does
|| > mean a change in the metabolic rate
|| > of the cells -- the oxygen consump-
|| > tion -- since brain ATP is essentially
|| > produced completely by aerobic
|| > metabolism.  Even if the energy is
|| > derived from local stores, you still
|| > need oxygen and that
|| > means blood flow.
||
|| These things are true in principle, of
|| course, but are you really saying
|| that the picomoles of K+ crossing the
|| neural membrane during an AP are
|| going to make a detectable dint in
|| the millimolar K+ extracellular
|| concentration a millimetre away?
|| [...]
|
| I've not researched Dr. Norman's
| comments, but can add, a bit, in-
| general with respect to =all= ionic-
| concentration dynamics.
|
| They are not restricted to small
| distances, be-cause each ion forms
| it's own "center-of-action", with
| respect to which, =all= of any
| individual ion's force-dynamics are
| carried with it.
|
| So, as an ion travels within the
| nervous system, its force-dynamics
| are acted-upon by the force-
| dynamics of everything that sur-
| rounds it -- which means, for in-
| stance, if there's an intense neural
| activation, there can be a =net=
| action upon an individual ion that,
| like a Child pumping a playground
| swing, impells the ion through
| relatively-great distances.
|
| These effects can, and do, operate
| within the whole brain.

=IMPORTANT= CLARIFICATION:

The net ionic effects correspond
to the net =ionic-force= dynamics,
and =not= necessarily to individual
ions' displacements.

This is the same-stuff that I dis-
cussed, in long-former posts, with
respect to genetic-material tuning -- 
how experience, at =all= of its various
'scales', is rigorously-coupled to
the DNA -- how the DNA is act-
ively-coupled, and tuned, via ex-
perience.

And that's about as Important as
things in Neuroscience get.

It's all worked-out, 'waiting' for
folks to receive it, in-person.

The rest of this post is the same
as my prior post.

ken [k. p. collins]

| These extended force-dynamics
| were, for instance, in the discussions
| of glial tuning of "memory" that I've
| discussed in long-former posts.
|
| And all of this is =easily= observ-
| able in the way that "memory"
| for widely-'separated' subject-
| realms can =only= be accessed
| via an intervening "pumping"
| stage.
|
| I experience this sort of thing
| routinely during my own research
| efforts [allowing myself to, once
| again, become "the lab-'rat'" :-], be-
| cause the subject matter that I
| deal with is multi-disciplinary.
|
| When I wish to focus on data
| that are widely-separated from
| any current focus, I've always
| got to do some work to "go" from
| the 'current' focus to the widely-
| separated focus.
|
| During this "going", I'm =not=
| 'relearning' everything that I've
| formerly-learned about the
| data-realm to which I'm "going".
|
| Although, yest, every 'time' I
| so "migrate" between data-
| realms, I do =always= learn
| a bit of new stuff [knowing that
| this new learning does always
| occur is some of why I've act-
| ively sought-out widely-separated
| data realms, and continue to
| routinely do so]. But what happens,
| in the main, when I "go" between
| widely-separated data-realms, is
| just a glia-mediated physical
| tuning of my brain's neural topo-
| logy. The necessary refs are cited
| in AoK.
|
| During this glia-mediated physical
| tuning, brains' neural topologies
| literally "morph", structurally, so
| that formerly-constructed micro-
| mods are brought into optimal
| 3-D structural conformation.
|
| All of this can be literally "watched"
| as it's happening [although, care
| is necessary while doing such
| "watching", else the data-realm
| "migration" that will actually occur
| will be with respect to the "watching",
| and not with respect to the problem-
| focus "memory" shift. :-]
|
| There are always stereotypical
| 'time' courses, during which one's
| ability to, for instance, express one's
| self optimally with respect to the
| migrated-from data-realm and
| the migrated-to data-realm varies
| inversly, one from the other.
|
| I can write volumes about this
| stuff, but the point I want to em-
| phasize, here, is as I discussed
| above -- the overall dynamics
| are =whole-brain= ionic-force
| dynamics in which individual ions,
| rather than being restricted to
| the dynamics of an individual
| neuron's activation-potential
| experience, are literally moved
| by the =net= ionic-flows in
| which they exist.
|
| All of this is flat-out easy to
| Verify via careful radioactive
| assays that follow 'individual'
| ions' cumulative flows.
|
| The problem in doing such
| experiments is that it's probably
| not ethical to impose radioactive
| quantities of fundamental ions
| within Humans, and doing it
| in 'rats' means that the data-
| realm "migration" becomes high-
| ly-subjective re. Experimenters'
| interpretations -- is the 'rat'
| actually "going" between wide-
| ly-separated data-realms? And
| how can that be externally-
| verified? Via widely-gualitatively-
| separated experimental perform-
| ance requirements?
|
| I've done it all in the ol' noggin'
| lab, and can show 'anyone' else
| in Neuroscience how to do the
| same.
|
| These things are a bit of what
| I want to discuss in-person with
| folks, and, a bit, of why I want
| to discuss stuff in-person with
| folks -- their discussion requires
| considerable attention to details
| that are readily-accessible, but
| which are routinely 'invisible' to
| folks who are untrained with re-
| spect to them.
|
| There's a =lot= of stuff in NDT
| that's analogous to this. I can't
| 'just' discuss it, in detail, in a
| "broadcasted" way be-cause it's
| a virtual Certainty that folks'd
| stumble upon only bits and pieces
| of the overall discussion, and, in
| such "incompleteness", 'fly-off-
| the-handle'.
|
| I cannot allow such, so I'm sit-
| ting here, wanting to share all of
| this stuff, in-detail, but having to
| 'wait' [interminably?] for in-
| person opportunity to do so.
|
| It's all so =Beautiful= that I'm
| left 'wondering' if there's anyone
| out-there who's actually interested
| in doing Neuroscience :-]
|
| Cheers, ken [k. p. collins] 





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