Itching theory?

Brad Wyble bradw at
Fri Feb 3 15:32:47 EST 1995

SOunds somewhat similar to an effect that can be observed using
vibration and muscle spindles.  If you vibrate the bicep while the arm
is upright and partially curled (about 60 deg from horizontal) and the
subjects eyes are closed, the sensation that the arm is slowly curling
more will be felt, causing the subject to extend the arm in
compensation.  The vibration stimulates the muscle spindles(I
think...its been a while), causing gamma motor neurons to fire.  This
causes the illusion that your muscle is contracting.  (I may have it bacwards)

In any case, could sensory neurons in the gums be reacting to the
vibration similarly?  Does the itch happen regardless of what part of
your mouth you're brushing?  And I also wonder how the frequency of
vibration affects the itch.

													-Brad W.

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