IUBio

The truth is out there

Andrew K Fletcher andrew.k.fletcher at naturesway.demon.co.uk
Fri Nov 27 14:50:56 EST 1998


Any spinal cord specialists out there who could help with this discussion?

Posted under heading: The truth is out there

If so,
could we please have someone put on record the current accepted mechanism
for cerebrospinal fluid circulation and formation? We need to have an
accurate benchmark, so that a new theory for fluid transport may be offered
for discussion. It is my belief that a new understanding of this phenomenon
will reverse a complete spinal cord injury.



F. Frank LeFever wrote in message <73l5ki$735 at dfw-ixnews8.ix.netcom.com>...

>My comments are interdigitated below:


>In <912075256.24982.0.nnrp-03.d4e44203 at news.demon.co.uk> "Andrew K
>Fletcher" <andrew.k.fletcher at naturesway.demon.co.uk> writes:

Hi Frank, Hi Ken,

The flow of water in plants and trees is relevant to this discussion,
it was
my interest in this that led directly to my working with spinal cord
injury,
ms and other neurological conditions.

I'd be surprised if the processes were the same (I.e. water transport
in trees,  CSF formation and transport and absorption).  What is your
thesis re relevance of CSF circulation to MS?  to spinal cord injury?

A few more surprises will follow shortly.

You have my word that in due course I will introduce my theory for fluid
transport into this discussion, but first of all I would like to hear from
people working in CSF exactly what they have got?

In Devon, UK, I went on the BBC Radio to talk about my work and a local
neurologist went confidently on the record as saying that ' Osmosis was
responsible for driving CSF'. and that this was the accepted mechanism.
I have studied the brief explanations in physiology books but cannot find a
reference to this. in relation to bulk flow.

>Frank, could you please summarise the content of 'this wonderful
>process'
>referred to in your posting and its relationship with how water
>reaches the
>leaves of trees.

>No, sorry, I could not.  Anyway, I thought you had listed the basic
>components of the processe(s) yet could not accept an explanation in
>these terms.

Are you familiar with the limit of 33 feet in physics for lifting water up a
single tube under normal atmospheric pressure  RE:Galileo and Torricelli?

>re your summary from the textbook account:  what's the publication date
>of that textbook?  If a later edition, was this section revised in the
>light of work done between earlier and later editions?

Principles of Anatomy and Physiology fifth edition 1987
Advanced Human Biology  1988
The relevance to these dates is of limited use as I am using them to try to
draw a conclusion from people in the field that is up to date. Furthermore
as nothing has changed in the literature RE: water transport in plants, I
suspect little if anything has changed in explanations for CSF circulation.


>I am no expert in this area, but it was clear to me from the
>presentations by the panel of very very expert neuroscientists at this
>NSF (National Science Foundation) satellite meeting (preceding the
>Society for Neuroscience annual meeting) that there were still
>questions to be answered regarding CSF sources, contents, circulation,
>and absorption and/or other clearance mechanisms.
>
>Much of what your summary says may be true, but much may be yet open to
>correction.  My own interest was not in mechanisms of circulation per
>se, but in the central focus of the conference, which was the extent to
>which neuroactive substances in the CSF could enter the CSF and reach
>targets via the CSF in sufficient amounts to be physiologically
>significant, and the kinds of long-term neural integration which might
>be subserved by this mechanism.
>
>F. Frank LeFever, Ph.D.
>New York Neuropsychology Group
>
>>
>>The flow of cerebrospinal fluid as described in Principles of Anatomy
>and
>>Physiology is as follows.
>>
>>The entire central nervous system contains  between 80 and 150 ml (3
>to 5oz)
>>of cerebrospinal fluid, colourless fluid of watery consistency.
>Chemically
>>it contains, proteins, glucose, urea and salts. It also contains some
>>lymphocytes.
>>
>>With regard to its circulatory function, cerebrospinal fluid delivers
>>nutritive substances filtered from the blood to the brain and spinal
>cord
>>and removes wastes and toxic substances produced by brain and spinal
>cord
>>cells.
>>
>>It then goes on to illustrate the path of the circulation of CSF.
>>
>>The flow of cerebrospinal fluid as described in Advanced Human
>Biology: J.
>>Simpkins, J.I.Williams, is as follows.
>>
>>Pressure compensation
>>CSF is produced from and returns to the blood passively in response to
>>pressure differences between the blood and CSF. The effects of
>increases in
>>blood pressure distending intercranial vessels can thus be reduced as
>more
>>CSF is produced.
>>
>>Page 125 The beating of the cilia cells sets up currents in the
>>cerebrospinal fluid, thus helping the circulation of metabolites.
>Astrocytes
>>are connected to the bases of ependymal cells which may assist
>exchange of
>>metabolites between CSF and neurons in the central nervous system.
>>
>>Fig 14.43, page 285 shows a simple drawing which illustrates the
>circulation
>>of fluids by arrows from the choroid plexus down one side of the spine
>and
>>up another side, it also shows a flow over the the surface of the
>brain,
>>indicated by an arrow on both sides.
>>
>>I did read an article, which was a reprint of text from another
>physiology
>>book, which I can't find, that stated something along these lines.
>>Circulation in the CSF occurs due to respiration, postural, and
>circulatory
>>influences.
>>
>>Ken Collins wrote:
>>
>>I've not studied it, but I expect the cerebrospinal fluid flows
>through
>>active
>>dynamics... when it's produced, it goes into the ventricles, more is
>>produced...
>>what was produced earlier flows to "get out of the way" of what's just
>been
>>produced. I don't know where the "drain" is... expect it's a
>distributed
>>thing,
>>too. ken Collins
>>
>>Original post.
>>
>>>>Could someone therefore sum up the accepted mechanism for
>circulation
>>>in the
>>>>cerebrospinal fluid, so that we have an independent benchmark for
>>>further
>>>>discussions? Only then will we see if this road leads us to any
>>>conclusions.
>>>
>>>
>>>- - - - - -(snip) - - - - - - -
>>>F. Frank LeFever, Ph.D. wrote.
>>
>>>I won't comment on his itemizing the forces by which water could be
>>>lifted up into trees and then demanding to know how this happens.
>>>(Incidentally, I found treatment of this wonderful process in
>Murchie's
>>>"The Seven Mysteries of Life" fascinating; too bad he got spooky on
>the
>>>last 2-3 mysteries...)
>>
>>>However, I too am interested in CSF, and attended a satellite
>>>conference (sponsored by NSF, prior to the Society for Neuroscience
>>>meeting early this month) on CSF as a communications system.  Among
>>>other things, problems of its circulation were considered.
>>>
>>>F. Frank LeFever, Ph.D.
>>>New York Neuropsychology Group





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