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On 20/02/2021 12:39, bill w wrote:<br>
<blockquote type="cite"
cite="mid:mailman.10.1613824773.658.extropy-chat@lists.extropy.org">
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000">The Secret Language
of Cells - Jon Lieff</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000"><br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000">I have never in my
life read such a book. Example: I knew about glial cells and
actually have mentioned them a few times in posts, reminding
everyone that neurons aren't all there is up there.</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000"><br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000">Little did I know:
thousands of different types, not only feeding neurons, as I
knew but communicating with other glial cells, capillaries
(which do far, far more than carry blood around), T and other
immune cells, choroid-lining cells, and so on. How many types
of glia? Thousands. Every progress in electron microscopes
yields more types of brain cells.</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000"><br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000">"Astrocyte signals
are different in each brain region, and for each individual
astrocyte. In addition, signals can be different in each of the
thousands of tiny protrusions on a single astrocyte."</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000"><br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000">How many types of
neurons? Thousands. How many types of neurotransmitters?
Thirty so far. Number of ways of communicating with other
cells: four so far. 1 - the well-known chemical communication
at synapses, 2 - electrical communication with other neurons, 3
- electrical communication with other types of cells, 4 -
signals taking place other than at the synapse.The first two
have to occur together.</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000"><br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000">Capillaries. Vital
building partners in all phases of tissue growth and
management. Sends signals to maintain normal metabolism;
regulate the growth of all tissue cells; get directions from
discussions (!) among stem cells, blood cells, tissue cells, and
local neurons, call for immune response help in cases of
infection and alerts T cells into action (chemical signals
through the bloodstream). When rebuilding damaged tissue,
capillaries communicate with stem cells to avoid production of
scars from excess fibers.</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000"><br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000">Just carrying
blood, huh!?</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000"><br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000">Brain waves: side
effects of neurons firing, right? In part. They can be signals
from one part of the brain to another telling it that a message
is coming, and then it does. <br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000"><br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000">Every paragraph
contains content that could be studied all of one's life.</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000"><br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000">What did I get out
of it? As I went along I saw how far we are from even thinking
of anything like uploading a brain. Every cell talks to more
than one other type of cell and in numerous ways.</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000"><br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000">Just totally
overwhelming - stunning. Usually I take a pencil and underline
important parts. Might as well underline everything. And yet I
could understand every word of it - written for the educated
layman. </div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000"><br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000">I did not read
every word. No point to it. Enormously influenced my ideas of
brain function, and how long it will take to really get a handle
on it, if we ever can do that.</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000"><br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000">p.s. the author
points out the fMRI does not measure neuronal activity, but
blood flow</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000"><br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:large;color:#000000">bill w</div>
</blockquote>
<br>
<br>
We could similarly observe the complexities of the structures of
cellulose and hemicelluloste fibres, their interactions with lignin
and other substances in wood, the many different grain patterns that
show up, the many different physical and chemical interactions with
other substances like metals and plastics, the physics and chemistry
of wound steel strings, the enormous numbers and complexity of the
wool fibres in felt, the ways that different types of glue behave in
bonding felt to wood, the frictional properties of metal pegs in
wooden holes, the physical properties of springs, and literally
thousands of other completely relevant and important things that
contribute to the structure and function of a piano, and conclude
that, in view of all this complexity, making another piano is
well-nigh impossible.<br>
<br>
The level of detail at which you study, understand and model a
system is important.<br>
If we don't consider this before starting, we end up lost in
impossible complexity, no matter what the system is. Even a spoon
has many levels of detail, and what you want to do in relation to
the spoon will determine which level you need to work at, what you
need to understand: It might be Polymer Chemistry, Metallurgy,
Engineering, Design, Ergonomics, etc. Nobody needs to use (or can
realistically understand) them all.<br>
<br>
We don't yet know exactly what level of detail is needed to model a
mind for the purposes of uploading, but it's unlikely to be so deep
that we might as well give up the attempt before even starting. Just
as an understanding of the physics of transistors isn't needed for
writing computer programs, I think it's doubtful that an
understanding of all the complex details of brain biology will be
necessary for mind uploading. There will be a level of detail that
is necessary and sufficient, we'll find out what it is, and we'll
use it just as a musical instrument maker uses his knowledge of
specific properties of certain woods and metals without needing to
know anything about chemistry or quantum physics.<br>
<br>
<pre class="moz-signature" cols="72">--
Ben Zaiboc</pre>
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