processing capability of the spinal cord

Richard Norman rsnorman at mw.mediaone.net
Sun Dec 6 14:46:53 EST 1998


"RonBlue" wrote in message <000b01be2143$345a2140$331bfbd0 at default>...
>"According to a book I
>read last Christmas (the chapters on neuroscience anyway)
>the spinal cord provides a very large portion of the processing
>required by many insects.  I asked a recent Ph.D. in neuroscience
>about this and he claimed it was nonsense
> <remainder snipped>

Technically, insects (like all invertebrates) have no spine and hence no
spinal cord!  Actually, they do have a longitudinal nerve cord with a
ganglion in each segment. It is true that the insect brain contains far
more neurons than all the nerve cord ganglia combined.  Nevertheless,
the segmental ganglia can produce a significant amount of complex,
coordinated behavior.  Headless insects can locomote, ventilate
their trachea, and conduct reproductive activity.  The classic example
is a praying mantis -- during mating  the female sometimes eats the
head off the male, but that does not stop copulation.  In fact it can
remove inhibitory controls and allow the male to continue with more
vigor!

As for vertebrate animals, do you know the expression "running around
like a chicken with its head cut off"?










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