Peripheral input WAS Re: micro mods to neurons

[Craig Hull]

COLLEEN M. SPECHT wrote:

[much snipped]
> p.s. there is much indirect evidence for "changes" in the nervous system in
> response to learning or situations where learning has taken place.  and i would
> make a "theoretical" argument for peripheral memories (which have also not been
> found) based on learned motor tasks.  briefly, you cannot master a piano with
> just a brain (i.e. central nervous system).  the connections between your
> motoneurons (to muscle tissue) are also plastic and this is probably, in part,
> how we 'learn' fine motor tasks.  And i am sure that it would not
> be any more independent of the cns than the cns is of the periphery.  they are
> not separate entities any more than the esophogus is of the stomach.  they just
> act differently, like the latter do, although they have a common goal.
> 
> we have to remember, the distinction between cns and pns is a man made one,
> even though they have many differences between them.
> 
> we also have to remember that memories are not necessarily conscious.  you
> remember how to ride a bike, but you are not aware of all of the processes that
> take place while you ride (i.e. when you are exhibiting that memory).
> 
> hope this helps!

Thanks for the replies.

Following on from the discussion of the nature of the central nervous 
physiology, I'd like to enquire more about the nature of the 
peripheral input. (I should point out that I am conducting research on 
insect sensory systems, so have not been exposed to much work on 
vertebrate systems). Never the less, an interesting paper has recently 
been published that makes certain postulates on the nature of the 
peripheral sensory input. It relates to feeding, but has other 
applications. Part of the model suggests (with some experimental 
evidence to back it up) that it is the total number of nerve impulses 
from a number of sensory cells that are required to form the input 
pattern of the "acceptable diet", ie across-fibre patterning. The 
important point is that depending on the quality of the previous diet, 
the firing patterns of the various sensory cells will change such that 
the behavioural feeding response is modified to take in deficient 
nutrients, but the total number of impulses for all the sensory cells 
would be roughly the same.

Any comments? Has there been much experimentation of this area in 
vertebrate systems, or are entomologists leading the way again?

Ref: Simpson S. J.  and D. Raubenheimer. 1996. Feeding behaviour, 
sensory physiology and nutrient feedback: a unifying model. 
Entomologia Experimentalis et Applicata 80: 55-64. 

Regards,
Craig.