RTA

iVillage Member
Registered: 03-31-2003
RTA
1
Wed, 04-02-2003 - 8:42am
"Unless the sample is documented, it is mere anecdote.. a peer-reviewed study is NOT anecdotal."

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.


iVillage Member
Registered: 03-27-2003
In reply to: doc2006
Tue, 04-08-2003 - 10:21pm
This supposition does not hold water--it is not the size of the part removed that determines the re-organization but the amount of innervation present in that part.

Please read this article on the re-organiztion after circumcision:

http://www.cirp.org/library/psych/immerman1/

"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."

I have had courses in Neurophysiology and checked my textbook. Now, granted it is sometime possible for peripheral axons to reconnect if severed, however, in higher vertabrates it is not possible for nerves to correctly reconnect to nothing.

And if all sensory endplates are removed, there cannot even be proliferation---- as those in the ridged band.

"The fact that sensory neurons can regrow when cut is not supposition. Consult the neurophysiology text of your choice."

"phantom limb syndrome is merely the heperexcititibility of the nerve "stumps"--nothing more and nothing less--or even perhaps to a "amputation neuromas".

"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.

http://www.cirp.org/library/anatomy/cold-taylor/

***This notion is in direct conflict with human and animal studies that show when a nerve is transected, and the distal tissue is amputated, the proximal nerve undergoes acute axonal swelling . After acute injury, the axon begins to sprout and branch at the injury site. Without the distal nerve, this frustrated attempt at re-innervation results in a bulbous, disordered tangle of axons, Schwann cells and fibrous tissue. Histology of the male circumcision scar shows amputation neuromas, Schwann cell proliferation and the bulbous collection of variably sized neurites. Amputation neuromas do not mediate normal sensation and are notorious for generating pain. Animal studies show that extirpation of the external genitalia results in acute retrograde degeneration of the nerve axon back to the spinal cord . Therefore, the changes in

circumcised male sexual behaviour may be related to a central nervous system alteration by retrograde axonal degeneration, or to peripheral nervous system damage by loss of the prepuce ridged band and amputation neuroma. It is assumed that amputation neuromas also form at the female circumcision scar, although we are unaware of a formal histology study."

Didn't you notice that ALL of the stretch receptors of the ridged band were lost?

"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."

Sorry, but the longest axon known to science is the giant squid axon. which is 1 meter long -max--all mammalian axons are MUCH shorter (if I remember correctly about 1". If they were longer the refrarctory period due to the NA-Cl pump would be prohibitiedly long.

"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.

Precisely, they are a sensory nerve ending--and if, removed, are lost, and the "nerve " is useless! The axon cannot generate a new sensory input in mammals. AND the stretch receptors of the ridged band are lost forever!!

"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."

http://www.usnewswire.com/topnews/first/0522-132.html

Study: Circumsision Results in Sexual Losses U.S. Newswire 22 May 14:30

******Sex researcher Tina Kimmel used the Semmes-Weinstein Sensory Evaluator to conclusively demonstrate that circumcision destroys men’s ability to detect delicate sexual stimuli.

The Semmes-Weinstein Sensory Evaluator consists of a series of SW monofilaments that can be applied to any anatomical region. They are used to assess damage of various ailments, diabetes for example.

Semmes-Weinstein monofilaments are calibrated nylon monofilaments. They generate a reproducible buckling stress and are identified by manufacturer-assigned numbers that range from 1.65 to 6.65. The higher the value of the monofilament, the stiffer and more difficult it is to bend.

Three monofilaments commonly used for testing are the 4.17, the 5.07, and the 6.10. Kimmel used SW monofilaments to measure her subject's ability to sense points of pressure on the glans of his penis.

Subjects were instructed to lie supine in a quiet area. They were blindfolded to eliminate visual input. Filaments are then applied perpendicular to the selected penile sites with enough force to cause the monofilament to buckle for approximately 1 second.

The researcher instructs the subject to say "yes" each time he senses the application of a SW monofilament. Five to 10 trials are to be taken at each site, and the subject must respond to 80% of the trials to be graded a given value at that site. If the subject is unable to sense at least 80% of the trials, he is tested with the next highest monofilament.

The results of the various test groups are then compared. Kimmel used groups of circumcised, intact, and restoring men.

She found that penile sensitivity of intact males is 25-30% greater than that of circumcised males. She also discovered the foreskin matches the lips and possibly exceeds the eyelids in sensitivity.

“Circumcision represents a true loss of sensation, it is not a diminutive harm,” said Kimmel.

Her initial findings indicate that restoring men gain back sensitivity, but never attain the sensitivity of men that were never circumcised.

This is perfectly understandable because restoring allows a man to slough off layers of dead, keratinized tissue.*****

"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.