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|Wed, 04-02-2003 - 8:42am|
Okay, I agree. Touche.
"Oh, then why are they now finding "The Living Brain" on PBS is showint that when an infant OR mature body part is removed, the corresponding part of the brain atrophies and is actually taken over by adjoining parts."
The distinction here is one of size. The loss of an entire limb, involving damage to both sensory and motor fibers results in disturbance of a significant area of both the pre- and postcentral gyrus of the cortex. However, the loss of a (relatively) small area of sensory fibers (even in a densely-innervated area such as the fingertip or oral mucosa) will impact only the postcentral gyrus, and a much smaller area of it, making recovery more likely.
"Again, I love the supposition, but find it lacking in a factual basis."
The fact that sensory neurons can regrow when cut is not supposition. Consult the neurophysiology text of your choice. This phenomenon is responsible for phantom-limb syndrome as well as the allodynia that often accompanies the selective loss of C fibers in peripheral neuropathies. AND it is responsible for the eventual recovery of sensation after trauma that cuts a peripheral neuron. I re-read the article at your request and do not see anywhere that it mentions the total loss of neurons when the foreskin is removed. Sensory fibers begin at the structure they innervare and travel all the way to the spinal cord before synapsing. Cutting the foreskin will result in the loss of PART of the neuron, but not the entire thing. The Meissner's corpuscle is not a nerve in and of itself, it is a nerve ending. The remainder of the nerve remains even when the Meissner's corpuscle is removed and has the capacity to regenerate.
After re-reading the article, I just don't find it very convincing. The basic message is that there are nerves in the foreskin. Any conclusions drawn beyond that are opinion, not fact. I am simply arguing that the article is no more valid than those that you so fervently dismiss as supposition.
"As stated, this is preliminary and the study so far indicates there is further loss of sensation subsequent to the nerve loss itself.. This study is ongoing. I can provide the methods used, etc..if you wish."
Yes, I'd love to see it.