neurotransmitter storage (all or one?)

Richard Norman rsnorman at mediaone.net
Fri Aug 25 14:10:22 EST 2000


Surely it IS correct.  Action potentials are widely misunderstood to be
the be-all and end-all of nervous system information processing.  They are,
indeed, useful and important for transmitting information over any "large"
distance, that is a few millimeters or more.  But at the cellular level, a
few
millimeters is an enormous distance and graded "analog" potentials along
with graded (analog) transmitter release form a large portion of the
information processing in local circuits.  The best example of this is
perhaps
the vertebrate retina, where the receptor cells (rods and cones), the
horizontal
cells, and the bipolar cells all do their thing without action potentials.
The
amacrine cells produce half-hearted action potential and it is only the
retinal
ganglion cells, who must send their output a long distance down the optic
nerve, that produces honest-to-goodness classical action potentials.

And in days past, there were large numbers of analog computers in use
doing all kinds of engineering computations and simulations -- adding and
subtracting, multiplying and dividing, even integrating and differentiating
in
the solution of complex systems of differential equations without the need
for a "On/Off" events.  Indeed, the very term "digital computer" was
necessary
to distinguish the newcomers from the ordinary, more common analog
variety.


"Theophilus Samuels" <theophilus.samuels at btinternet.com> wrote in message
news:8o6f77$ri1$1 at plutonium.btinternet.com...
> > > It sounds as though the brain is sorta like a computer that is not
based
> on
> > > binary.
> >
> > Right.
>
> Surely that is incorrect? The fundamental principle used by computers
relies
> on 'ON' and 'OFF' events, or in binary form, 1's and 0's. Now consider the
> neurons working within the brain. Essentially, all they do is initiate
> action potentials that either produce excitatory or inhibitory responses -
> 1's or 0's. Thus, you can actually say that the brain does indeed work on
a
> binary system IN principle. The MAIN difference between the binary system
> used within a CPU and a brain, is that neurons are capable of firing at
> differing rates, i.e. information in the brain is FREQUENCY coded. So to
> reiterate, the firing of neurons does indeed use a binary principle to
> create, well...., you or I.
>
>   T.L.S.
>
> <dag.stenberg at helsinki.nospam.fi> wrote in message
> news:8o55if$nvm$1 at oravannahka.helsinki.fi...
> > Phoenix <phoenix42 at uswest.net> wrote:
> > > It sounds as though the brain is sorta like a computer that is not
based
> on
> > > binary.
> >
> > Right.
> >
> > > Since the computers we
> > > currently used are binary based, I wonder if we'll have to develop new
> > > computers that aren't binary based ...
> >
> > Before digital computers, there were analog computers.
> >
> > Dag Stenberg
>
>







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