left-right reversal of CNS: Why?

kenneth paul collins KPCollins at postoffice.worldnet.att.net
Tue Sep 3 18:36:08 EST 1996

Henry... the left-right "reversal" to which you refer occurs 
ubiquitously within mammalian nervous systems for one reason...

The nerve-fiber termination distributions that result align with the 
totally-inhibitory outputs of the cerebellum so that the problem of 
activating the muscles to move away from environmental sources of 
noxious stimulation can be resolved by "simply" minimizing the 
topologically-distributed ratios of excitation to inhibition (TD E/I) 
occurring within the neural architecture...

This pain-avoidance problem is infinitely-large in scope... yet this 
"simple" neuroanatomical solution typically resolves it in millisecond 
time frame... so this neuroanatomy-based problem-solving strategy has 
extraordinary survival value...

The anatomical antecedants of the the bilateral crossing phenomenon 
("decussation") can be traced all the way back to organisms exhibiting 
radial symmetry... coelenterata... jellyfish...

BTW, I've developed a theory of nervous system function that traces such 
neural architecture throughout the entire CNS... the 
information-processing significance of the fiber crossings extends 
strongly all the way into the highest-"level" realms of cognition...

ken collins

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