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k p Collins kpaulc at [----------]earthlink.net
Wed Jan 21 15:28:47 EST 2004

One brief addendum below.

[Find it [and any such addenda to any of
my lengthy posts] by scanning the left-most
column as one "scrolls" the text.]

"k p Collins" <kpaulc@[----------]earthlink.net> wrote in message
news:i0APb.18021$i4.349 at newsread1.news.atl.earthlink.net...
> Go to the bottom.
> "Dag Stenberg" <dag.stenberg at nospam.helsinki.fi.invalid> wrote in message
> news:bum896$bqe$1 at oravannahka.helsinki.fi...
> > In bionet.neuroscience Dag Stenberg
> <dag.stenberg at nospam.helsinki.fi.invalid> wrote:
> > > In bionet.neuroscience k p  Collins <kpaulc@[----------]earthlink.net>
> wrote:
> > >> How does the brain feed-forward to the
> > >> retina during dream-sleep?
> > >
> > > I am not sure it does. Efferent connections to the retina are not so
> well known.
> > > I'll have to check it up.
> >
> > It seems that "A centrifugal visual system (CVS) involving brain
> > connections to the retina that influence ganglion cell responses has
> > long been established in birds and there is evidence that such a system
> > also exists in different mammalian species (Repérant et al. 1989 for
> > revue, Shütte 1995).
> >    "These results demonstrate a direct serotonergic retinopetal
> > projection in the mouse stemming from the dorsal raphe nucleus whereas
> > in the pigeon a similar projection system relays via retinal projecting
> > cells in the NIO.
> >    "...CVS involvement in retinal melatonin synthesis and coordination
> > of circadian rhythms (rodents) to visual attentional mechanisms related
> > to enhanced processing of information concerning novel or meaningful
> > stimuli within the visual field (birds).
> >
> > The above from Miceli et al., an abstract at
> >
> .htm
> >
> > "This indoleamine-accumulating retinopetal pathway may be involved in
> > retinal melatonin synthesis, coordination of circadian rhythms, and
> > interocular phenomena." Schutte, in Vis Neurosci. 1995 Nov-Dec; 12(6):
> > 1083-92.
> >
> > There is a lot of literature on a CVS in fish. There is an olfactory
> > projection to the retina in fish. And reptiles have a CVS.
> >
> > "Centrifugal fibres arising in brain nuclei and passing back to the
> > retina have been noted sporadically in mammals but with few details and
> > no ideas about which brain centers they might derive from. Centrifugal
> > fibers are particularly well developed in the avian retina (Cajal, 1892;
> > Maturana and Frenck, 1965; Ogden, 1968). A few centrifugal fibres were
> > described in the monkey retina by Polyak (1941) and later by Honrubia
> > and Elliot (1970). According to Polyak (1941) the centrifugal fibres in
> > monkey have varicose, bulbous terminals that end in the inner plexiform
> > layer close to amacrine cell bodies. In the human retina they have been
> > followed across the nerve fiber layer into the inner nuclear layer
> > before disappearing (Honrubia and Elliot, 1968) (see below).
> >   "Recently, it has been discovered that centrifugal axons arising in
> > the hypothalamus project to various parts of the brain including the
> > retina in the macaque monkey. Interestingly these axons contain
> > histamine (Gastinger et al., 1999).
> >   Gastinger, M.J., O'Brian, J.J., Larsen, J.N.J. and Marshak, D.W.
> > (1999) Histamine immunoreactive axons in the macaque retina. Invest.
> > Ophthal. Vis. Sci. 40, 487-495.
> >
> > The above citation was from http://webvision.med.utah.edu/fbloops.html
> >
> > "It is suggested that the projection from the nucleus oculomotorius to
> > the retina constitutes a link in the multisynaptic efferent pathway from
> > the visual cortex to the eye, by which the visual cortex can influence
> > the functioning of the retina." a rat study by Hoogland et al., Neurosci
> Lett.
> > 1985 May 23; 56(3): 323-8.
> >
> > On the other hand, a year before, Schnyder and Kunzle had reached a
> > negative conlcusion:
> > "The results yielded no compelling evidence for the existence of a
> > direct retinopetal pathway in the rat, which is in contrast to a
> > recently claimed retinal projection originating from the pretectum.
> >    "This finding is discussed with regard to the possibility that also
> > in the rat the lateral tegmentum exerts an early influence on visual
> > input, but at the "higher" collicular level and not at the "original"
> > retinal one.
> >    from Schnyder and Kunzle, Exp Brain Res. 1984; 56(3): 502-8.
> >
> > It seems from my literature search that people after 1987 more or less
> > gave up finding a relevant and functional retinopetal connection in
> > mammals, and turned to fish and birds. The Gastinger paper is an
> exception.
> >
> > Dag Stenberg
> Thank you for looking-up these refs. They are along the lines of
> the other post that I recall reading. I'll have to look deeper, but
> I'll be surprised if my hypothesis is not born out.
> It doesn't require a lot of retinal reed-forward, because there's no
> EM that needs to be processed, so a relatively-few inputs to the
> retinal ganglia would be all that was necessary for there to be
> enough retino-fugal activation for the TD E/I-minimization
> mechanisms to converge with respect to it.

And, thereby, 'tune' it's image-'coherence' [in the inherently-
'loose' relam of dream-imagery, as far as 'coherence' goes],
by feeding-back into the retinal feed-forwards.

Dream-imagery is 'entertainment' that, 'normally', gives 'comfort'
to the nervous system while it's doing the massive 'database'-
integration work that occurs during, and is the main information-
processing purpose of 'sleeping'-consciousness.

What about "nightmares"?

I expect that, if careful differential analysis is done [even via EEG]
folks'll find prefrontal correlates of "warning learning" [AoK, Ap5]
in-there. The brain is just rendering the "nightmare"-imagery loosely-
'coherent' with the "prefrontal forces" [AoK, Ap7] that are being
actualized within itself. [And there's also probably another kind of
correlate - with respect to 'breaking-out' of sleeping-consciousness
because the minimal monitoring of the external environment that's
active during sleeping-consciousness has been 'triggered' by relative-
ly 'unfamiliar' environmental conditions. This last stuff is easy to Test.]

k. p. collins

> This's is =roughly= commensurate with the fact that waking and
> dream imagery are observably not the same - while dream im-
> agery can be vivid, it's always 'ghostly' relative to waking-imagery,
> and the vividness can be ascribed, at least in part, to "recognition"
> dynamics as they are discussed in AoK, Ap6 - like the way that
> the brain can extrapolate [hypothesize with respect to] a 'whole'
> image from experiencing only a relatively-small part of it's 3-D
> rotational "signature" [also discussed in AoK, Ap6].
> With respect to the refs you cite, it =might= be, like happens
> all the 'time', right across all of Science, that the retinal efferents
> got 'laughed-off-the-stage' of investigation [and folks, wanting
> not to suffer the same, were induced to 'move away from'
> looking for them. This sort of thing happens =all the 'time'=
> within all of Science. [There was an article in The =New York
> Times= yesterday that discussed brecisely this set of things
> in the midst of the heights of Physics. Takes a bit of Fortitude
> to stay-the-course, despite the 'laughter' [and worse].]]
> I've confidence in the hypothesis I've presented for all the
> reasons that I've discussed in prior posts. It's extremely
> energy-efficient, and recreating "the image", internally, has
> =zero= advantage, over leaving it upon the retina.
> I knew before discussing the hypothesis that it'd be 'contro-
> versial', which is one of the reasons that I decided to discuss
> it. It's good to have a case that evokes 'passionate' discussion,
> because it's then that folks actually start Thinking. TD E/I(up)
> that enables TD E/I(down) :-]. And as far as the hypothesis
> being 'weird' is concerned, virtually everything I've done in
> both NDT & TH suffered that same 'condition' with respect
> to folks' early responses, yet virtually all of both theories
> has withstood all challenges. It's just more of the same.]
> If existences of the retinal inputs are sustained, I expect,
> that the hypothesis I've presented will also be sustained.
> It =really= 'respects' the work that has to be accomplished
> within the brain, and the 'image-within' view does not do
> so =at all=, and, since the neural Topology and its functioning
> are 100%, otherwise, aligned with the former, if the latter
> is True in this instance [if my hypothesis with respect to
> the =imagery= is incorrect], then that'd  be the sole example
> of anything within the entire nervous system that 'violates'
> this 'Respect' for energy-consumption. [This 'Rule' is also
> discussed throughout AoK, and is explicitly-stated in
> Ap3.]
> So I'm Grateful for the refs you've cited, and will look-deeper
> into the problem, following these leads you're shared.
> [And, if folks 'wonder', I did Choose the 'date'.]
> Cheers, Dag, ken [k. p. collins]

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