[ExI] book on cells - TMI !!!!

[Ben]

On 20/02/2021 12:39, bill w wrote:
> The Secret Language of Cells - Jon Lieff
>
> 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.
>
> 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.
>
> "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."
>
> 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.
>
> 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.
>
> Just carrying blood, huh!?
>
> 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.
>
> Every paragraph contains content that could be studied all of one's life.
>
> 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.
>
> 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.
>
> 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.
>
> p.s. the author points out the fMRI does not measure neuronal 
> activity, but blood flow
>
> bill w


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.

The level of detail at which you study, understand and model a system is 
important.
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.

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.

-- 
Ben Zaiboc

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.extropy.org/pipermail/extropy-chat/attachments/20210221/fd3d1d9a/attachment.htm>