IUBio

the liver and the brain

r norman rsn_ at _comcast.net
Wed Sep 1 18:02:37 EST 2004


On 1 Sep 2004 14:41:18 -0700, rscanlon at nycap.rr.com (ray scanlon)
wrote:

>The motor program generators are established in the developing nervous
>system by the DNA. When triggered, they produce motor activity. We
>ask, "How are they triggered?"
>
>The sensory neurons transduce the energy of the universe as it arrives
>at the body surface. They also transduce energy from the internal
>condition of the body. The resultant signal energy filters through the
>interneurons and, when it summates at a given motor program generator,
>it triggers the generator.
>
>The paths that the signal energy traverses are originally set up by
>the DNA. I emphasize that the nervous system is precisely connected
>before and after birth to be prepared to handle an unfriendly universe
>that previous generations encountered. When the organism meets up with
>the present milieu, there is a tremendous pruning and die-off of
>synapses and neurons.
>
>There is a reorganization of synapses (called learning by some) as the
>organism masters the location of food and water sources and the
>position of secure resting places. Later there is the problem of
>mates. The paths through which the signal energy passes are altered so
>that the appropriate motor program generators are triggered so as to
>ensure survival.
>
>First place is given to avoidance of the predator.
>
>Ray

This is about the most simplistic explanation of behavior that I have
ever heard.

In some ways, it reminds me of a paradigm briefly held in the 50's or
60's to describe invertebrate nervous systems.  This was the time of
the original discovery of central pattern generators in motor systems
and complex pattern recognition in sensory systems.  This was the time
of the discovery of "command neurons" in crustacea.  This was the time
of the analysis of "fixed action patterns"  in behavior and "signed
stimuli" in sensation.  A complex stimulus is processed by sensory
filters and triggers a command neuron that generates a complex motor
act.  Reality quickly outran this oversimplified model.  Everything
interacts with everything else.  Wherever you look you find
plasticity.  Especially in mammals, seemingly everywhere you look you
find plasticity necessary as an essential part of the adaptive
behavioral response.

In another posting on this thread, I presented many references to
experimental work discussing this topic.  Ray, if you want people to
take you seriously, it is time to stop talking in the most simplistic
and general terms.  Be specific.  Describe a specific pattern of
behavior, describe exactly what your model predicts for that behavior,
and describe an experiment that can critically test whether or not
your story has any basis in reality.  Better yet, do what every
scientist must do in order to get funds to operate the lab:  review
the current literature critically to show that your model has
substantial credibility and that it has the ability to succeed in
explaining phenomena that existing models do not. 

If you cannot do this, then please remove bionet.neuroscience from the
list of news groups you post to.  Your BS might be quite acceptable
for philosophy, cognitive science, or neural net discussion (though I
think not), but definitely does not belong in neuroscience.





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