September 13, 2010 | David F. Coppedge

Nerve Traffic Cop Identified

What makes signals go in one direction in neurons?  It’s important, because a reflex signal from a bump on your knee needs to go in the direction of the controlling muscle and on to the brain, not any which way.  Is there some kind of traffic cop that directs the placement of “one way” signs in nerve cells?  Indeed there is.  According to a press release from the University of Georgia, it’s the enzyme MEC-17.
    Researchers were not attempting to cure a disease or derive an application from finding this out; they just wanted to know how it works.  How do neurons know which direction to send the signals?  It appears that MEC-17, which they studied in roundworms, zebrafish and human cancer cells, is responsible for placing the traffic signs, called acetylation marks, on the cellular highways made of microtubules.  The paths with lots of these marks are on the sending end, and the paths with few of them are on the receiving end.  When the marks are not set properly, bad things happen: zebrafish develop neuromuscular defects, and humans are subject to debilitating neural diseases like Parkinson’s, Alzheimer’s and Huntington’s.  This discovery may lead to new treatment strategies by enhancing or inhibiting the action of MEC-17.
    By noticing that MEC-17 works identically in animals as diverse as roundworms, fish and humans, the researchers deduced that “this microtubule acetylation process using MEC-17 is an evolutionarily conserved function.”  Conserved means un-evolved.

Saying evolutionarily conserved is like saying “aimlessly straight.”  It’s a meaningless phrase we should not be duped into thinking signifies anything logical.  This discovery emphasizes once again that things do not just happen; specific parts that are functionally exquisite are necessary for function.  One question the research team appeared to overlook, though, is what controls MEC-17?  If this enzyme puts up the signs, who is the foreman?  We are certainly not consciously controlling much of this in our bodies.  Most of it happens without our knowledge.  It’s like the infinite regress question: who watches the watchers?  The hierarchy of design must eventually stop at a Designer who is omniscient and omnipotent.

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