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[Neuroscience] Re: LTP and STDP

Benjamin via neur-sci%40net.bio.net (by Benjamin from verizon.net)
Tue Feb 20 04:59:05 EST 2007


<Cervellone from gmail.com> wrote in message 
news:1171929647.679166.20910 from v45g2000cwv.googlegroups.com...
> On 19 Feb., 08:19, "Benjamin" <Benja... from verizon.net> wrote:
>> <cervell... from gmail.com> wrote in message
>>
>> news:mailman.136.1171827170.4140.neur-sci from net.bio.net...
>>
>>
>>
>> > Hello everybody
>>
>> > while studying for my Masters in neuroscience i am learning a lot but i
>> > dont
>> > always understand everything immediately. So i'd like to pose some
>> > questions.
>>
>> > For LTP it is necessary that Glutamate and Glycine be bound at the same
>> > receptor. So i was wondering where the Glycine is from. Is it co stored 
>> > in
>> > the same vesicles as Glutamate?
>>
>> > In Spike Timing Dependent Plasticity (STDP) experiments, stimulation of
>> > adjacent retinal Neurons by spike trains  causes a change in 
>> > intracortical
>> > connections in V1. These translate into a receptive field orientation
>> > change
>> > in V1 and this leads to a shift in the percieved postition of the
>> > stimulus.
>> > BUT  the percieved postition change and the receptive field change  are 
>> > in
>> > oppostite directions to one another.
>> > I dont understand why. Is ist because retinal images have to be 
>> > mirrored
>> > because of lens passage?
>>
>> > If someone is interested: The article i got  it from  is : Spike timing
>> > dependent plasticity, from synapse to perception by yang dan and 
>> > mu-ming
>> > poo; physiol rev  vol 86
>>
>> > Thank you for your time
>>
>> > Jean-Pierre
>>
>> If the inverted-displacements you discuss
>> are traced-through the integrated nervous
>> system, it turns out that the 'difference' cor-
>> relates exactly with, and implements, abil-
>> ity to act with directionality that is optimally
>> 'appropriate' with respect to the stimulus
>> set.
>>
>> The easiest way to begin to see this is by
>> cross-correlating the "mirror-image" map-
>> pings of primary sensory and motor cortices,
>> which automatically inverts "acted-upon"
>> and "act-upon" neural dynamics, which is
>> all extremely-elegant because it enables
>> the learning of motor behaviors that use
>> prior sensory neural activation as "templates",
>> the only intervening thing necessary being
>> the 'blindly'-automated minimization of the
>> topologically-distributed ratios of excitation
>> to inhibition ["TD E/I-minimization"] that oc-
>> cur within 'the' nervous system.
>>
>> It's a sub-dynamic within the automation-
>> of-knowing.
>>
>> The stuff you shared with us is a particularly-
>> delightful instance of the globally-distributed
>> order which rigorously maintains "Direct-
>> ionality" so that convergence can occur via
>> simple TD E/I-minimization.
>>
>> Thank you for posting your discussion,
>> Jean-Pierre.
>>
>> Cheers, k. p. collins
>
> Hello K P
>
> I am very sorry, but i didnt undestand a lot of your explanation. You
> use i think a lot of computational neuroscience terms im not familiar
> with. Could you explain maybe in physiological terms?
> What is TD E/i minimalization and how does it relate to STDP ?
>
> Thanks
> Jean-Pierre

First, I realized, after I posted my pre-
vious reply, that my comments are
True only if the phenomena the pap-
er you cited are True -- I've not read
the paper, nor was I previously aware
of the specific stuff you discussed.

On to your current post:

'stdp' are non-information-containing
=artifacts= of TD E/I-minimization.

=Nothing= is 'timed' within nervous
system function.

=Everything= is determined by en-
ergy-gradients.

Big-difference.

The so-called "oscillations" that
researchers have 'presumed' to
be 'correlated' to "information-con-
tents" are just artifacts of global-
ly-integrated TD E/I-minimization.

For instance, the convergence with-
in neural activation that occurs 'with-
in' the hippocampus occurs as a
result of an alternation of specific-
ally-ordered and stochastic [having
a 'random' component' activation,
during which alternation, the 'columns'
'in' the hippocampus "latch" TD E/I-
minimized 'states', 'holding' them
while other 'columns' are in the proc-
ess of also "latching" TD E/I-mini-
mized 'states'.

The =illusion= of there 'being' 'osc-
illation inherent' occurs as a non-
information-containing =artifact=
of the fact that convergence toward
an in-the-momentary-dynamics
net TD E/I-minimization-guided con-
vergence is, in fact, occurring.

The "signature" of such is a stereo-
typical diminution of high-frequency
'components' of the overall activation
[refs including excellently-diagrammed
data are cited in AoK, Ap5.]

But, because of the stereotypical dim-
inution of high-frequency neural act-
ivation 'components' -- which is 'just'
what TD E/I-minimization =is= -- re-
searchers, not comprehending TD E/I-
minimization, 'presumed' that the
stereotypical 'picture' 'constitutes'
"oscillation".

It doesn't.

All of this discussion to provide you
with Verification that =nothing= is
'timed' 'within' nervous systems.

When folks assert otherwise -- that
this or that is 'timed' within neural
activation dynamics -- they're just
'jumping-on-the-bandwagon' of some-
thing that has become 'fashionable'
simply because it's been repeated
so routinely.

It's 'funny' actually -- because, when
one actually understands what in-
formation-containing 'oscillations'
would actually 'mean', one sees that
the folks who 'jump-on-that-band-
wagon' of merely-reiterated 'opinion'
are actually 'asserting' that they can
do stuff by 'looking into crystal balls' -- 
just like 'astrologers' and 'fortune
tellers :-]

For, if =anything= were 'timed' in
neural-activation dynamics, it'd
'have to' =know=, apriori, the nec-
essarily-'correlated' 'timings' that
'occur' within the external-environ-
ment.

'fortune-telling' :-]

In all of physical reality, there's
=nothing= that is 'timed'.

What has been referred to as 'time'
has no physically-real existence.

All there is 'within' physical reality
is =energy=, flowing in Determin-
istic accord with the one-way flow
of energy, from order to disorder,
that is what's =described= by 2nd
Thermo [WDB2T.]

When folks invoke non-physically-
real 'time' and/or 'timing', they're
'just' adding an 'imaginary layer'
to physical reality, in much the
same way that ancient Astrono-
mers 'presumed' to add non-
physically-real 'epicycles' [lit-
tle 'loops'] in the paths of objects'
orbits.

In Science, such 'extraneous'
stuff only 'blocks' understanding.

I saw through it 'decades' ago.

It's part of why folks find the work
I've done to be 'hard-to-compre-
hend'.

Folks 'move toward' invoking non-
physically-real 'time' [and other
non-physically-real stuff] simply
because, since all of this Falsity
has merely been repeated so
much and so routinely, folks' nerv-
ous systems have converged up-
on TD E/I-minimization that liter-
ally incorporates the Falsity into
subsequent neural-activation dyn-
amics.

And "woe to any" who work to
lift folks up out of the Falsehood
that they've come to 'love' be-
cause of the prior TD E/I-min-
imization that has occurred 'with-
in' their nervous systems :-]

I want so much to convey the full-
essence of NDT to people like
you, Jean-Pierre, who obviously
have the 'fire-within', that I Ache
because I can only discuss via
a posting-sequence that's been
occurring for 'decades'.

So I can't reiterate everything in
every post.

I've tried, above, to give you the
'nut-shell' that's most-relavant
to the concerns you addressed.

Cheers, Jean-Pierre,

ken [k. p. collins] 




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