Transmitters and receptors and nicotine (Was Re:June Gloom)

[From Bjorn Simonsen (2005.06.24,13:40 EST)]

From Bill Powers (2005.06.23.1559 MDT)
Sorry, I'm not following your thinking at all. Maybe if you could answer
some of the questions I have here I might understand better.

Well that is my fault. I will try again. Maybe you can call attention to
where I am wrong.

That doesn't answer my question. Why are you assuming that the effect of
the nicotine is on comparator neurons rather than on neurons that are part
of perceptual functions or output functions?

I don't assume that. I don't know if nicotine has effect on the comparator
neurons, perceptual functions or output functions. But nicotine has an
effect some places. That is my knowledge. And I can explain "why" for
myself.

I don't see that simply exciting a higher frequency in some neuron means
that a reference value has changed. All I can see is that the
proportionality constant between the input to some neuron and the output
from it has changed. That is not a change in a reference signal. It's just
a change in a proportionality constant.

If the perceptual signals at one level are changed by a proportional factor,
you find the effect of the proportional factor in _the perceptual signals at
the level above_, and you find it again, in the output signal at the level
above. But the reference signal at the level where we started is a matrix of
the output signals above. Then there is a change in reference signal. What
is wrong with this?

Let us start with what you can see.
If you open Rick's hier.exl and think upon the three levels as level 4, 5
and 6.
If you multiply P4,1 .... P4,6 with the proportional constant _G_, you will
find that constant also in the Output value at the _level above_ because the
perception signals at this level (above) include G. (not really so in
hier.exl, but...)
If the Output signals at level 6 is changed because of G, then the reference
signals at level _5_ is changed.

Let me be clearer. Why isn't the effect of the nicotine that you speak of
simply an effect on the neurons in a perceptual input function, so that for
the same input signals they produce larger output signals? Are you
proposing that nicotine selectively affects only those neurons that are
found in comparator functions?

Not in comparator functions, but see below.

So are you saying that comparators are specialized to use acetylcholine as
their neurotransmitters?

No. But in the brain there are a lot of different transmitters.
Acetylcholine is one type. Glutamate and atropine are other transmitters. If
I was a Brain specialist I would have known many more.
There are a lot of different receptor proteins. All transmitters don't react
with all receptor proteins. It is just where aceylcholine are the
transmitters, nicotine has affect (I think).
That are the places where I am saying nicotine has an effect.
This can be in a region where you find the perceptual signal (at one level)
or the comparator or the output signal. Doesn't matter. See above.

bjorn

[From Bill Powers (2005.06.24.0627 MDT)]

Bjorn Simonsen (2005.06.24,13:40 EST) --

I don't assume that. I don't know if nicotine has effect on the comparator
neurons, perceptual functions or output functions. But nicotine has an
effect some places. That is my knowledge. And I can explain "why" for
myself.

Yes, the physical effects can be explained. But now it seems to me that you're jumping from saying that nicotine amplifies certain effects of signals to saying that you have an explanation for nicotine addiction. But all you have shown is that nicotine will disturb the operation of some control systems no matter where it acts in the nervous system (and I agree to that). This is a long way from explaining any specific behavior. What you're saying could "explain" any result of smoking at all -- or its opposite, if the opposite occurred instead. When an explanation remains true no matter what happens, it ceases to be an explanation.

You are saying, it seems to me, that because nails have the properties of nails, and wood has the properies of wood, you have explained why there are houses.

Best,

Bill

[From Bjorn Simonsen (2005.06.24,1617 EST)]

From Bill Powers (2005.06.24.0627 MDT)
Yes, the physical effects can be explained. But now it seems to me that
you're jumping from saying that nicotine amplifies certain effects of
signals to saying that you have an explanation for nicotine addiction. But
all you have shown is that nicotine will disturb the operation of some
control systems no matter where it acts in the nervous system (and I agree
to that). This is a long way from explaining any specific behavior. What
you're saying could "explain" any result of smoking at all -- or its
opposite, if the opposite occurred instead. When an explanation remains
true no matter what happens, it ceases to be an explanation.

Well nicotine addiction has been in back of my head (or front of it?). But I
also know many people smoke a cigarette now and then and they don't have to
lighten one. Addiction is maybe more a statistical concept than a
biological/chemical concept.
Now I confine myself to your words: "But all you have shown is that nicotine
will disturb the operation of some control systems no matter where it acts
in the nervous system (and I agree to that)."

bjorn